New Focus Optical Mount Questions
What differentiates a New Focus optical mount from others on the market today?
We designed our optical mounts to provide precision adjustments that will really stay put. In addition to using thicker frames and stiffer springs for stability, all our mounts are based on a true kinematic design-that is, there is precisely one constraint or actuator for each independent degree of freedom. To provide even more precision and durability, we use sapphire seats; these ensure that repetitive adjustments do not leave tracks which could make positioning non-kinematic, and therefore non-deterministic and imprecise. Then, to make mounts with exceptional long-term stability, we minimize slop in the screws themselves. For this, we developed a proprietary screw-assembly process with very tight tolerances to achieve the smooth feel in our screws. We limit the amount of grease in our actuators because large amounts of grease would cause the threads to migrate over time and from temperature variations, leading to long-term creep. The result is a mount with very smooth movement and high precision as well as exceptional long- term and thermal stability. Just compare one of our screws with one from another company; you'll notice the difference right away. Also, try the "snap" test with one of our mounts in your lab. Put the mount in an interferometer and "snap" the mount joints by separating them a short distance and letting them snap back (to prevent damaging the sapphire seats, be careful not to stretch the joints too far). This will give you an indication of the quality of the construction of the mount. With the sapphire seats, thicker frames, and stiffer springs, our mounts will return to the same starting position.
How much angular adjustment do the mirror mounts have?
All of our mirror mounts (Standard and Pint-Sized Mirror Mounts and Miniature Mirror and Platform Mounts ) have ± 4 degrees of maximum angular adjustment, except for the Model 9774 and Model 9775 mounts, which have ± 2 degrees of maximum angular adjustment.
What's the repeatability of the Model 9897 Flip-Up filter holder?
The 9897 Flip-Up filter holder has a repeatability specification of ± 0.005 inches in the down position.
What's the best way to maximize the Flipper's repeatability?
1. Flip gently. In our tests, the Flippers perform better when flipped carefully rather than allowing them to make a snapping noise. This is largely due to the fact that one adjustment screw will deform over time when it snaps against the base.
2. Make sure the sapphire seat isn't damaged. Inspect the sapphire seat in the base of the Flipper. This is a clear disk that supports the adjustment screw in the "arm". If the sapphire is damaged, cracked, or broken, return the mount and we can replace the damaged seat.
3. Make sure the optic is secure. We recommend using an epoxy if the optic is not going to be changed.
4. Make sure the Flipper is securely mounted. Sometimes when the Flipper is mounted on a pedestal, the flipping motion can cause the pedestal to rotate a little each time it flips. Use a threadlocker or epoxy to secure the Flipper to the pedestal, then you can also use an epoxy to secure the pedestal to the optical table in addition to a holding fork.
Post and Pedestal Questions
How does the stability of a post compare to that of a pedestal?
These two mounting systems will perform differently in your experiment because they react differently to forces such as vibrations or the force of your hand when making adjustments. These forces create movement of your optical elements, which can affect your experiment. For example, the motions of the mirrors that make up its cavity often determine the frequency noise in a laser. This motion is also apparent during alignment of your optical system. The amount of motion caused by your hand during alignment is determined by the stiffness of the post or pedestal.
For example, we designed our post holders with a lockable cam lever that distributes a large force evenly against the post. When locked, the post and post holder are nearly as solid as one piece. This gives you much better stability than conventional post holders that only lock with a screw. However, even this may not be stable enough for all applications. To test which provided more stability, we compared the deflection of a post versus a pedestal. In our experiment, the pedestal system showed much less deflection for a given force due to its larger diameter and increased stiffness. A stiff mounting system will also perform better when excited by acoustic vibrations.
How to maximize your stability?
The way you mount your optics can make the difference between a stable setup and one that suffers from vibrations. When building a setup, be sure to minimize beam height, use fewer parts (for instance, use a single post or pedestal rather than stacking them), and use parts made of thick, stiff material such as steel. We offer two different mounting systems for your experiments-posts with post holders and pedestal risers. Posts with post holders are the more conventional alternative and are particularly convenient because they offer continuous height adjustment. Pedestals, on the other hand, offer significantly more stability because of their 1" diameters, but are available only in fixed heights. For your convenience, they come in a variety of heights and if you need those in-between heights, try our Model 9950 pedestal shim set.
Screw Questions
How do I install the precision 80-pitch screw and nut sets?
New Focus precision 80-pitch nuts are designed for easy installation in your equipment. Following these guidelines will ensure easy installation and the best results:
1. We recommend using an adhesive when mounting the nut in a slip-fit hole. Do not press-fit the nut or it may distort.
2. It is important to mount the nut such that any axial force is taken up by the mounting range. Axial force should not be carried by the adhesive.
3. We recommend using Loctite 609 Cylindrical Bonder as the adhesive. It is essential that both surfaces be completely free of grease for proper curing of the adhesive. Are the balls used in the adjustment screws hardened? Yes, we use a hardened-steel ball bearing made from stainless 440C with a hardness specification 58 Rockwell "c".
Where can I get a tap for the 1/4-80 and 6-80 screws?
If you need a tap for our 1/4-80 screws and our 6-80 screws, you can get a tap from either of the two companies listed below:
Balax Inc.: 262-966-2355
Cleveland: 800-474-1283
OEM Version Questions
I need a special mount for a commercial application. Does New Focus offer special products for OEM use?
All the products that you see in our catalog (and some that you don't see) are available for commercial original equipment manufacturer (OEM) use. We work hard to develop partnerships with our commercial customers-from making custom products for a specific application, to simply laser-engraving your company's name or model number on one of our standard products. Some projects developed specifically for customers have even evolved into catalog products. For example, our low-cost Valu-Mount and high- performance top-actuated mounts are the results of partnerships between New Focus and other companies.
Still, most of the work we do for our OEM partners never shows up in the catalog. For instance, we've developed a proprietary process for bonding optics to mirror mounts that minimizes wavefront distortion, added dowel-pin holes and pre-aligned optics for drop-in operation, customized our 4-axis aligners, and custom-labeled products with our customers' names to meet the needs of a variety of customers.