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Frequently Asked Questions (FAQs)
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The recommended cleaning methods are dependent on the type of optic and its coatings. You can download the recommended CVI Laser Optics and Melles Griot cleaning procedures document Cleaning Methods (PDF). The first part of the document describes five separate cleaning procedures with step-by-step instructions. The second part of the document lists which procedures should be used for which component. You can also download this article Cleaning Optics (PDF) which explains the importance of the cleaning process to improve both the lifetime and performance of optics. Proper materials, techniques and handling procedures should be used to minimize the risk of damage. |
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The recommended cleaning methods are dependent on the type of optic and its coatings. You can download the recommended CVI Laser Optics and Melles Griot cleaning procedures document Cleaning Methods (PDF). The first part of the document describes five separate cleaning procedures with step-by-step instructions. The second part of the document lists which procedures should be used for which component. You can also download this article Cleaning Optics (PDF) which explains the importance of the cleaning process to improve both the lifetime and performance of optics. Proper materials, techniques and handling procedures should be used to minimize the risk of damage. |
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Yes it is. In our previous catalogs, we sold the laser heads and the power supplies separately, whereas in our new catalog we have grouped them together to be sold as systems. We found that most people ordered both the laser head and its appropriate power supply on the same orders, so we decided to sell them as a system to make it easier on the consumer. The 05LHP151 is the part number for just the laser head while the new system part number 25 LHP 151-249 designates the same laser head with its corresponding US power supply. We understand that our customers may only need to buy just the laser head or just the power supply, so we still sell them individually. Commonly, we can still supply a laser head or power supply, but just haven't listed it in the catalog or on the website. This particularly applies to our older components. Most of the time these are still available and can be purchased by calling us directly. Simply contact the CVI Laser Optics and Melles Griot's Applications Engineering department to find the appropriate parts: Customer Support. |
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There are many times when it is inconvenient and impractical to put a large laser on the top surface of a tabletop. For this situation, CVI Laser Optics and Melles Griot has a shelf designed to fit under the tabletop that allows a laser to be mounted below. The beam is then steered using mirrors to the tabletop surface via a laser port allowing the entire table surface to be used for an experiment.
To place an order for this system, there are four key points to remember:
- Append /H to the end of the product number of the desired tabletop for Laser Ports and all the appropriate mounting holes for laser shelves and beamsteering systems.
- Order the desired size of the Under-Table Laser Shelves. (07OTS001-007)
- Order the corresponding size of the Shelf Supports. (07OTA003-005)
- Order the desired StableRod Beam Steering System. (07BSF023-523)
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The power connector/cord we use is a Mouser Electronics #172-4201 (mouser.com / tel. 800-346-6873). Ref. Shutter Pwr Cable - Mouser 172-4201.pdf
The recommended power supply is 12VDC, regulated, 3 Amp (providing some "reserve" over the 2.5A max load). |
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The cost of manufacturing optics is extremely volume dependent. Mass-produced lenses provide excellent performance at low cost. Lenses produced in small quantity can cost five to twenty times more. It is always worth attempting to use or adapt a mass-produced lens for an application before designing a custom lens. |
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Optical mounts for on-line applications should be rigid, have positive locks, and have no more than the required adjustments. Laboratory mounting fixtures are generally not rugged enough for permanent on-line installations. |
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For direct TTL control of shutter "ON" time, DIP switches DS-1 & DS-2 should be ON. DS-3 should be OFF. On-board timer pot R3 should be set to it's minimum value (full CCW). Maintain the TTL pulse as long as required to get desired shutter timing.
For on-board control of shutter "ON" time, all DIP switches should be ON. Initiate the shutter drive with a short TTL pulse (i.e., 20mS). Set on-board timer pots as needed to get desired shutter timing.
Notes - The shutter will not actuate if DS-2 and DS-3 are both OFF. See Operating Instructions sheet #25164B for more complete information. |
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Thread pitch is the distance between adjacent threads measured parallel to the thread axis. From the standpoint of threaded drive mechanism like a micrometer or a thumbscrew, thread pitch defines travel for exactly one rotation of the knob. For example, since the 07 MAT 703 Fine-Touch thumbscrew has a thread pitch of 125um, its spindle will travel 125um per each rotation of the knob. Thread pitch for inch parts is specified in terms of threads per inch (TPI). |
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The Pump & Go Isolators are the first step up from simple rigid legs. They are a simple and economical alternative when ultra stability isn't required. These isolators are intended for applications such as Bioimaging, Raman spectroscopy and Micropositioning. The isolators contain a reinforced rubber air mount to act as a soft damped spring. The Pump & Go isolators have also been designed to operate for long periods of time without consuming air. Air can be adjusted with a simple foot pump through a standard Schrader valve located near the bottom of the leg.
The SuperDamp Isolators provides both vertical and horizontal dampening. These isolators are intended for applications such as Interferometry, Holography and Single-mode fiber alignment. Vibrations from the floor are dampened by passing air through two chambers. The resistance this air meets at the interface of the chambers helps to dampen the vertical vibrations. A design similar to that of a pendulum uses gravity to reduce the horizontal vibrations that the may effect experiments on the table. The SuperDamp Isolators are an active system. To allow for changes in load distribution, these isolators have a self-leveling system. The isolators allow for a range of motion of 13mm to compensate for an uneven floor. As a reminder, a continuous airflow must be supplied to these isolators.
The main structure of all our isolators is the same, allowing for the rigid and Pump & Go to be upgraded if needs and applications change. |
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The pellicle beamsplitters will generally reflect 5 to 20% more S polarized light than P polarized light, depending on the coating and wavelength. For a more specific performance estimate, please contact one of our Applications Engineers. |
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CVI Laser Optics and Melles Griot offers an extensive line of laser safety eyewear which covers most common laser applications. Because of the complex requirements for laser safety, we recommend that you contact one of our applications engineers and let us recommend the product that can best protect your vision. To do this, we need information about your laser and application. Please download and fill out the Laser Safety Eyewear information request form provided below before contacting the applications engineer. Laser Eyewear Form (PDF) |
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Machine vision optics should be mounted firmly but should not be stressed by excessive force. Do not rely on the camera C-mount thread to support heavy lenses. Either mount the lens and let the camera be supported by the lens, or provide support for both. Avoid over-tightening lens mounting clamps. |
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If this is happening, then you have mounted the translation stage with its micrometer pointed upwards and there are two ways to fix this problem: 1) Mount the translation stage so the micrometer is pointed down or, 2) remove the stage from the "L" bracket, mount any one of the 07 BMA-series mounting plates to the bottom of the stage and remount the stage on to the "L" bracket so that the top of the stage is in contact with the "L" bracket. |
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Helium Neon lasers can range from 800 MHz to 1575 MHz full-width-at-half-maximum (FWHM) depending on the design. The typical 632.8nm HeNe is 1400 MHz. The width of a single mode located under the gain curve is typically 1 MHz. |
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In the catalog the different parts are labeled A through E. For a complete system you would need to choose one part from each of the letters.
A: Choose either an open or paneled lower frame. The height of the frame is 36". These frames will accommodate any manufacturers tables provided the outside dimensions are the same. There is approximately a 1" gap between the table and the enclosure on all four sides of the table.
B: There is only one size of upper frame for our enclosures. The distance from the lower frame to the top of the upper frame (where the translucent windows fit) is 36".
C: The sliding windows are not essential to the enclosure system but do help provide isolation between the experiment and outside air turbulence in the lab.
D: The accessory shelf allows the user to keep instruments which may interfere with the experiments (due to vibrations from a fan or pump) away from the work surface. The shelf hangs down approximately 17" from the top of the upper enclosure and is 22" wide.
E: When you purchase the paneled lower frame (letter "A") the center section on all four sides will be open. This option allows the user to fill in these sections with either doors or panels. There is also the option of filling these spaces with rolling utility cabinets. |
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For standard (black-painted metal) shutter blades, the transmission is essentially zero. |
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While re-gassing can provide some extension of the output performance in some gas lasers like the CO2, Argon and the higher powered side arm HeNes (which have external optics), it is not recommended or provided for smaller internal mirror coaxial tubes. Typical end-of-life failure for a HeNe is cathode sputtering. This occurs when the protective oxide layer on the cathode is expended through continuous bombardment by the laser discharge. There is no cost effective way of regenerating this layer. When the oxide layer is expended, the discharge itself vaporizes the "raw" aluminum and deposits this material, in its vapor state, on other surfaces such as the optics and the glass bore. |
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Increase the f-number (decrease the aperture size). This may require increased lighting. However, very large f-numbers (>f/22 image side working f-number) will significantly degrade the lens resolution. |
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Rotating two wedge prisms of equal power about an axis parallel to their adjacent faces, a beam can be steered in any direction within 4X the wedge deviation angle. Wedge prisms can be held using the 07 HPW 001 wedge prism adaptor and can be rotated using the 07 HPR 221, 07 HPT 231 or the 07 HPT 731 polarizer rotators. |
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Most of the time, yes. The optic & coating combinations shown on the Buy-Online section are our most popular ones, and are the most likely to be readily available. Our full selection of antireflection and high-reflection coatings can be applied to our line of optics for an additional fee. For coating recommendations, availability, and pricing please contact one of our Applications Engineers. |
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First of all, a tabletop would need to be chosen based on a few parameters. For more detail on choosing the system, please see the following link. Selecting and Optical Table.
1. Choose the tabletop size. 2. Determine the performance requirements. 3. Determine the tabletop thickness. 4. Add desired options. Second, a leg support system would need to be chosen based on your application. 1. Determine the performance requirements. 2. Determine the length of the leg. (A standard final table system height is 36".) Third, any accessories like instrument shelves for the system would need to be chosen. 1. Determine type of shelving. 2. Determine size of shelving. |
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Maximum allowable light level will depend on many factors (wavelength, duration, blade material, blade coating, and environmental conditions), generally limited by coating damage and/or warping of shutter blades. Although we do not rate shutters for specific light levels, we can provide sample blades for application-specific testing by customers. Contact CVI Laser Optics and Melles Griot Applications Engineer for sample blade arrangements. |
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No. The image from a telecentric lens remains in focus over the same depth of field as that of a conventional lens working at the same f-number. Telecentric lenses provide constant magnification at any object distance. Therefore, they make accurate dimensional measurements over a larger range of object distances than a conventional lens. |
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When the shutter blades are fully open (or fully closed for a normally open shutter); a dry contact is made with the X-synchronization, which provides electrical continuity. |
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Most of our HeNe laser heads are CDRH / CE certified. Certified product for CDRH falls under one of the following classifications: Class II (<1.0mW), ClassIIIa(<5.0mW) or Class IIIb(<575mw). For CE our lasers are certified as a class 2 or 3B. Plasma tubes including some laser heads are not certified. In this case, it is the responsibility of the end-user to certify their system by meeting agency approvals. If CDRH / CE certification is a requirement for your system, be sure to verify the laser you select meets your needs. |
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The one main advantage the flexure mount has over the kinematic mount is its ability to support heavier loads. The flexures provide significantly more vertical support than the springs in kinematic mounts. |
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For a comparison of the breadboards, the following data has been calculated for each of our 0.9m x 1.2m breadboards. UltraLight Series Optical Breadboard Part Number: 07OBG563 Size: 0.9 x 1.2m Page #: 39.5 Resonance Frequency: 150Hz Dynamic Deflection Coefficient: 2.9xE-3 Relative Tabletop Motion: 0.59nm Deflection Under 250lb. Load: 54.36µm Performance Series Optical Breadboard Part Number: 07OBH563 Size: 0.9 x 1.2m Page #: 39.7 Resonance Frequency: 292Hz Dynamic Deflection Coefficient: 1.1xE-3 Relative Tabletop Motion: 0.22nm Deflection Under 250lb. Load: 4.18µm PerformancePlus Series Optical Breadboard Part Number: 07OBI563 Size: 0.9 x 1.2m Page #: 39.9 Resonance Frequency: 294Hz Dynamic Deflection Coefficient: 7.4xE-4 Relative Tabletop Motion: 0.15nm Deflection Under 250lb. Load: 3.94µm UltraPerformance Series Optical Breadboard Part Number: 07OBC513 Size: 0.9 x 1.5m Page #: 39.11 Resonance Frequency: 172Hz Dynamic Deflection Coefficient: 2.2xE-3 Relative Tabletop Motion: 0.45nm Deflection Under 250lb. Load: 16.50µm |
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Yes, we can! Our ability to modify includes edging diameters down and cutting to square or rectangular shapes. This includes lenses (both spherical and cylindrical), mirrors, and filters (excluding the interference filters). There are a few rules of thumb to follow when modifying standard pieces: The standard tolerance for modifications is ±0.25 mm (±0.01"). If a customer needs a tighter tolerance, it must be specified. A standard lens can be edged down to a diameter that is no less than twice the center thickness of the lens. For example, we smallest we could edge a beginning diameter of 30 mm and center thickness 8.4 mm is down to 17 mm. A mirror can be modified, but the flatness cannot be maintained to the original specification because stress is induced when a piece is modified. We can also use CNC processing to create 1-off pieces in a myriad of size and radii options. And, finally, we make custom lenses in larger batches for many customers and applications. |
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In optics, "distortion" is the name of a specific aberration inherent in lens designs. Telecentric lenses offered by CVI Laser Optics and Melles Griot have low distortion. However, low distortion and telecentricity are separate, unrelated lens parameters. |
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Yes. In general, all drives (thumbscrew, micrometer, differential and motorized) with equivalent travel ranges have the same mounting interface. In this specific case, the 07 TLC 224 has a travel range of 13 mm as does the 07 MAT 703 so it will fit properly. |
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We recommend only using the recommended 4X voltage pulse for 20mS; Using any lesser voltage will result in less reliable shutter actuation. |
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All CVI Laser Optics and Melles Griot HeNe lasers have a recommended Laboratory or Module power supply (AC and DC input versions available), typically listed on the laser's specifications sheet. If you are unsure which one is appropriate, please call us at 1-800-835-2626 and ask for a Laser Applications Engineer. Rule of thumb in choosing a power supply: If you know the operating voltage and current of your laser, the power supply must have a voltage range large enough to fit the operating voltage for the laser and must be set at the appropriate operating current. |
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No. By definition, a telecentric lens has a fixed magnification. CVI Laser Optics and Melles Griot offers a variety of telecentric lenses with large selection of magnifications. |
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No, the drive can reach better resolutions. The micrometer has graduated markings or "incremental marks" whereas the thumbscrew drive does not. Since resolution is generally understood to be the smallest movement an actuator can make, it can be highly dependent on the person who makes the adjustment. For comparative purposes, resolution on drives with "incremental marks" is referenced in terms if the smallest incremental mark which on most micrometers is 10um. The actual smallest movement the micrometer can make is one half to a third of the smallest incremental mark. |
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Shutters operated outside these conditions may function reliably.
Specifications:
Operational
Maximum Repetition: 2 Hz Minimum Recharge Time: 200 msec (from de-energized to next actuation) Duty Factor: < 100% (NOTE 1) Service life: >100,000 actuations
Environmental
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Coherence length is defined as the length over which energy in two separate waves remains constant. With respect to the laser, it is the greatest distance between two arms of an interferometric system for which sufficient interferometric effects can be obtained:
Lc=c/Dn L Coherence length will vary from laser to laser as a function of the Doppler broadened gain width; however, for a HeNe 20 - 30 cm is typical. |
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Both of these products take un-polarized input and convert it to linearly polarized output. The main difference is the Taylor is air spaced and the Thompson is cemented. The advantage of the cemented prism (Glan-Thompson) is that it has a greater field of view (as great as 24 degrees depending on length). The air spaced prism (Glan-Taylor) only has around a 10 degree field of view. The advantage of the air spaced is that it has a higher transmission than the cemented Glan-Taylor. |
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Yes, we can! We can also put a reflective coating on one of our plano-concave (or plano-convex) lenses. |
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Because the first element of a telecentric lens must be larger than its field of view, telecentric lenses are generally restricted to fields of less than six inches. Larger fields of view are possible in some applications, including web inspection, using line-scan cameras. |
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We do not have a documented laser damage threshold for our Spring-Steel Blades with a Teflon-impregnated black matte finish. If this is a concern for your application CVI Laser Optics and Melles Griot will send you a shutter blade for testing. |
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It depends on how accurately you are able mount to your actuator. When mounting an actuator, the goal is to minimize contact-point friction. Contact-point friction is the result of a misalignment between the actuator tip and the contact point and obviously, a round tip interfaces to a flat contact point and vise versa. Contact-point friction for a flat-tipped actuator increases as the center of rotation of the actuator's spindle is offset from the center of the round contact point. For a round-tipped actuator, contact-point friction increased the more the axis of rotation of the actuator's spindle is angularly misaligned to the flat contact point. |
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We have recently announced a new service to coat Customer Furnished Materials. Please see the link below for our press release. Any further questions should be directed to the contact information at the bottom of the press release. |
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Both types have advantages and disadvantages. Crossed-roller bearings can handle higher load capacities and are more resistant to permanent damage from drops but they tend to be more expensive and are more sensitive to bearing-way contamination such as dirt particulates. Ball bearings are less expensive and more resistant to bearing-way contamination owing to point contact with the bearing way. |
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The GLC Collimating and Focusing Lenses and the GPA Standard Mounted Anamorphic Prisms are compatible with each other. The 830, 405 and 375 nm GLC parts (except for GLC-50.0-20.0-830) indeed have the same 8.0-mm clear aperture for interchangeable use. The links below are for the two items discussed above: GLC Collimating and Focusing Lenses GPA Standard Mounted Anamorphic Prisms The collimator lens can be inserted into the input side of the Mounted Anamorphic Prism housing. It is held in place with a set screw. |
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The 2 OrthoPins are located in two separate compartments on the side of the stage opposite the micrometer. Setscrews must be removed to gain access to the OrthoPins. |
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Yes. You can motorize one of our 07 MHT 225 or 07 MHT 227 kinematic mirror mounts using two of either the 07 EAS 503 or 07 EAH 503 stepper-motor drives, and the 17 BSC 002 stepper-motor controller. Simply remove the thumbscrew drives from the mirror mount and replace them with the aforementioned stepper-motor drives. A third stepper-motor drives can be added as well if needed. |
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No, the calibration date listed on the filter spectral curve sheets are the next calibration due date for the spectrometer on which the curve was measured. It has no effect on the filter's performance. |
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Yes. The 07 EAS 503/F or 07 EAH 503/F stepper-motor drives can be used to provide 13 mm of automated travel for a 40 X 40-mm center-drive translation stages. For mounting to an optical tabletop, either the 07 RPC 016 or 07 RPC 516 adaptor plate is needed depending on whether the stages is inch or metric. |
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S-polarization (the s stems from the German word senkrecht meaning perpendicular) and P-polarization (the p means parallel) are the two main ways to describe two types of linearly polarized light. A primary misconception when using the terms is assuming that P is always vertical and S is always horizontal. This is not true. P and S are relative to a surface (usually the surface that the light is acting upon and/or reflecting from).
To properly define S- and P- polarizations, we first need to define the term plane of incidence. The plane of incidence is the plane that the incident and exiting beams lie in and is perpendicular to the surface that the light is incident upon.
P-polarization refers to light that is polarized parallel to the plane of incidence.
S-polarization refers to light that is polarized perpendicularly to the plane of incidence.
So saying that P-polarization is always up-down and S is always side-to-side is incorrect. One example where this is incorrect is with a common beamsplitter setup. In a beamsplitter being used where the entrance and exit beams are all parallel to the table top, P will parallel to the table (side-to-side) and S will be perpendicular to the table (up-down).
The best thing is to keep in mind that S and P are relative to the plane of incidence. |
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Yes, by using either the 07 EAS 504/F or 07 EAH 504/F stepper-motor drive, and the 17 BSC 002 stepper-motor controller, any of the 65X65-mm translation stages with 1 inch (25 mm) of travel can be motorized. For mounting to an optical tabletop, the 07 ORA 509, 07 RPC 013 or 07 RPC 513 adaptor plates is needed. |
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Unfortunately this will not work. The micrometer in a 07 TLC 224 65X65-mm, 13mm travel translation stage or any 13-mm-travel translation stage has a 9.5-mm mounting diameter and the 25-mm travel micrometer has a 10-mm mounting diameter and will not fit. A 07 TLC 224/A, however, is available with 25 mm of travel. |
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There are no kitted systems available but one can be made from any of the 25-mm travel, 65X65 translation stages having a side-mounted micrometer and a 07 EAS 504/F stepper-motor drive. |
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Diffractive Optical Elements (DOE's) can focus light just like conventional refractive elements but do so by diffraction (similar to a grating) instead of by refraction. Compared with conventional optical surfaces, which are flat or spherical in shape, DOE's can be constructed to simulate complex surface shapes to better correct aberrations and improve optical performance. Just like glass optics, DOE's can be antireflection coated with single or multilayer coatings. DOE's are useful for conventional broadband imaging applications as well as for many low- and high- power laser applications. Typical DOE sizes range from approximately 4 mm to 250 mm in diameter. For OEM applications, the principal advantages of using DOE's include: DOE's usually permit a reduction in the number of optical elements in a design, reducing costs and lens weight. DOE's often enable optical performance that would be impossible to achieve using conventional optical elements alone. |
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A flexure is a, strictionless device that relies upon the elastic deformation (flexing) of a solid material. Sliding and rolling are entirely eliminated from the design. The flexure device is limited to applications where the required travel is typically no more than 10-15% of the major dimension of the device. In addition to having no internal friction, flexure devices have high stiffness, high load capacity, and high resistance to shock. They also exhibit a low sensitivity to vibration. Users should be aware that in all standard flexures, there is a second-order cross coupling between axis. This movement is called arcuate motion (travel is in an arc motion). For fine positioning applications as in fiber optic alignment, and integrated optics, this is seldom a problem. In addition, if precise rectilinear movement is required, then compound flexure devices eliminate the arcuate motion and are readily available. |
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There are three "traditional" technologies used in motion positioners — dovetails, ball bearings, and roller bearings. Each of these technologies have their respective strengths (e.g.: high load capability, long travel), however, they all have varying degrees of friction and stiction. This fundamental property causes wobble, hysteresis, and/or backlash, and an uncertainty in reproducibility — limiting their practical usefulness to precision of 0.1 mm at best. Conversely, because of the, strictionless nature of a flexure based positioner, precision on the order of 1 nm are readily achievable. Also, because of the stiffness of a flexure design, maintaining a specific position is greatly enhanced. This sort of high precision and stiffness are mandatory in applications requiring (100 nm accuracy such as single mode fiber optic alignments integrated optics and pig tailing.) |
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Piezoelectricity or pressure-electricity is a property of some crystalline materials. When these materials are compressed, they produce a voltage proportional to the applied pressure. Conversely, when an electric field is applied across the material, there is a change in its shape. Piezo-ceramics can respond rapidly to changing input voltages (microsecond time constants) and their positional resolution is limited only by the noise of the power supply. Traditionally, high voltages (1 to 2 kV) were required to produce the desired extensions from the piezo material. This limited their acceptance because of the high cost of power supplies, noise, and reliability. CVI Laser Optics and Melles Griot has developed a piezo electric material that operates in the 0 to 75 V range; eliminating the traditional problems associated with piezo actuators. These new state-of-the-art devices can be coupled to our line of flexure stages yielding a positioning device capable of 5 nm precision. |
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Piezoactuators are not ideal voltage-to-displacement transducers — they exhibit nonlinear properties of hysteresis and drift. Although these properties can be overcome by approaching the final destination from one direction (unidirectional approach), a more powerful technique to eliminate them is to use a "feedback control" loop. CVI Laser Optics and Melles Griot has developed a range of piezoactuators with a closed loop position feedback sensor. The linearity response of these closed loop devices are better than ±0.5%, a d the noise equivalent motion is 5 nm. |
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The autoalignment piezoactuator controller, CVI Laser Optics and Melles Griot's automatic alignment controller, is used with our piezoelectrically controlled positioners to simplify and speed up the time-consuming alignment procedures normally experienced when testing or fabricating single-mode fiber optical components. It makes alignment automatic, signal acquisition takes a fraction of a second, alignment is maintained indefinitely, and it compensates (in real time) for movements caused by environmental disturbances. |
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The elegant analog system used by the autoalignment piezoactuator controller employs a principle previously used by radar engineers to track their targets. By rotating the cone of light emitted from a source fiber, the light entering the target device is modulated at the frequency of rotation. This modulation is recovered by the autoalignment piezoactuator controller's detectors and compared to the phase of the signal used to rotate the source fiber. This information is decoded into vertical and horizontal components of displacement and used to close the loop on the source fiber. Consequently, this process brings the fiber and device into precise alignment. Displacement errors are decoded in a few cycles of modulation, typically several milliseconds; consequently, alignment is achieved in less than a second. |
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Unlike other alignment techniques, which use either programmed scanning algorithms or video processing techniques, the autoalignment piezoactuator controller's operation does not require a computer. It operates independently, ensuring at all times, that the critical axes are maintained in precise alignment. This occurs while other concurrent operations are carried out, usually under the control of a computer. |
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The autoalignment piezoactuator controller solves the major problems of: 1. Acquiring an initial throughput signal and then maximizing it through constant active adjustment of the appropriate axes of a piezo positioner — normally the vertical (Z) and horizontal axes (Y). 2. Compensating, in real time, for micrometer scale misalignment in Z and Y, caused by interaction between axes, as axial displacement (X), pitch (y), yaw (z), and roll (x) are adjusted for optimum throughput power. 3. Correcting environmental disturbances caused by temperature changes or vibrations. |
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In its more usual configuration, the autoalignment piezoactuator controller provides continuous and automatic optimization of coupled power, between, for example, a fiber and an I/O device - by servo controlling the vertical and horizontal axes of a positioner fitted with piezoelectric actuators. When a throughput signal is first acquired, the autoalignment piezoactuator controller immediately optimizes this signal by adjusting the vertical and horizontal position of the fiber. This takes a fraction of a second. Tracking is then initiated and the user is able, with the use of an additional positioner, such as a flexure roll stage to optimize the angular axes. |
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A pitch (y) adjustment will interact principally with the Z axis, causing vertical misalignment, yaw (θz) will tend to misalign Y, while roll (x) will interact with both Y and Z. However, the autoalignment piezoactuator controller actively compensates for any interaction between axes by constantly and automatically maximizing the vertical (Z), and horizontal (Y) axes. |
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A CRT display provides real-time visual control of the alignment process. It displays the autoalignment piezoactuator controller's operating parameters, indicating the extent and direction of the piezo electric movements, both vertically and horizontally — i.e., the position of the circle, and the modulation depth — i.e., the diameter of the circle. The upper right hand corner of the screen represents the maximum piezo extension position. By maintaining the scanning circle on the screen, the user ensures that piezo travel limits are not exceeded — and that loss of throughput signal never occurs. |
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It is practical to use more than one autoalignment piezoactuator controller in a single optical path simultaneously. To achieve this, a user must specify two controllers set to different scanning (modulation) frequencies. The autoalignment piezoactuator controller utilizes highly selective phase sensitive detectors, which detect only their own frequency. This allows multiple alignments to be achieved in a single optical path from a single detector. |
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Yes, the autoalignment piezoactuator controller has the ability to accommodate movements between a device and fiber during a pig tailing operation. However, when attaching fibers, two options are available, depending on the response of the throughput signal to the bonding process itself. 1. Remain in TRACK mode — The autoalignment piezoactuator controller follows any relative movements by constantly and automatically optimizing throughput power. 2. Switch to LATCH mode — this freezes the vertical and horizontal positions at optimum coupling. |
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Yes, the autoalignment piezoactuator controller is hardware rather than a software product. It is not based on a software algorithm but uses an instantaneous analog technique to accomplish alignment. |
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When you need to read absolute position at the nanometric level. For example in applications such as: (a) Near-field measurements — where position and power levels must be mapped. (b) When precise position adjustments are required - to compensate for misalignment during welding or soldering processes. (c) Ultra critical control of the fiber standoff distance. |
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