Optics Cleaning방법및 제품소개
ㆍ작성자: 전재필	ㆍ작성일: 2009-12-02 (수) 11:48	ㆍ조회: 3019
www.edmundoptics.com (Down:749)

Caring for Your Optics

Dust and stains on an optic can cause scattering, and impurities on the optic surface can react with incident laser light to damage optical coatings. With proper handling and cleaning of your optics, you can prevent damage and ensure their continued performance.

General Tips

If it’s not dirty, don’t clean it! Handling optics increases their chances of getting dirty or damaged, so you should clean optics only when necessary.
You should handle optics in a clean, lowdust environment while wearing powderfree acetone-impenetrable gloves or finger cots. Since oil and debris from your hands or from used lens tissue can stain or damage optical coatings, you should not touch any transmissive or reflective surface of your optic and never reuse a lens tissue. Remember that lens tissues are inexpensive compared to the price of an optic.
Inspect an optic for dust and stains by holding it near a bright visible-light source. Viewing the optic at different angles allows you to see scattering from dust and stains.
Step 1. Use a clean-air duster:
Dusting is always the first step in cleaning your optics.
Wiping a dusty optic is like cleaning it with sandpaper. So always dust with compressed and filtered air or nitrogen before wiping any optic. If the dusted optic has no visible stains after you dust it, then remember: “If it’s not dirty, don’t clean it.” If it’s still not clean, proper use of solvents and lens tissue can often do the trick.

Wiping a dusty optic is like cleaning your windshield with sandpaper. Always blow the dust off your optic with compressed filtered air or nitrogen before further cleaning it.
Step 2. Use solvent and lens tissue:
The way to use them depends on the optic, but always wipe slowly and clean the edges first.
Glass-cleaning solvents will streak, and tissue paper or a t-shirt will scratch, so always clean optics with reagent- or spectrophotometric- grade solvent and a low-lint tissue manufactured for cleaning optics. Always use lens tissue with a solvent, because dry lens tissue can scratch optical surfaces. A good solvent to use is a mix of 60% acetone† and 40% methanol. (Acetone alone dries too quickly to dissolve all of the debris. The methanol slows the evaporation time, and also dissolves debris that acetone alone would not clean.) Isopropyl alcohol is safe and effective, but its relatively slow evaporation can leave drying marks on the optic. Cleaning your optic’s edges before cleaning its faces prevents dirt from being drawn up onto the face. Wiping slowly allows the solvent to evaporate without streaking. Remember, slow and steady cleans the optic.

†NOTE: Always use acetone-impenetrable gloves when using acetone.
The “Drop and Drag” Technique
The “drop and drag” technique is ideal for light cleaning of unmounted optics, such as our Model 51XX mirrors, and Model 580X beam pick-offs.
Place your optic on a clean, non-abrasive surface, such as a clean-room wiper. After blowing off the dust using compressed air or nitrogen, lay a piece of unfolded lens tissue over the optic, drop on some solvent, and slowly drag the soaked tissue across the optic’s face.

Drop solvent onto your lens paper and drag the soaked tissue slowly across the optic’s face. Remember to clean the edges of your optic before you clean the face.>

The “Brush” Technique
Use the “brush” technique for small optics, such as our mirrors and beamsplitter cubes.

NOTE: When cleaning Model beamsplitter cubes, avoid getting solvent into the gap between the two prisms that make up the cubes, as this will break the bond between them.

Wipe slowly straight across from one edge of the optic to the other.
Make a lens-tissue brush by folding the lens tissue so that the fold is as wide as the optic to be cleaned. Do not touch any part of the tissue that will touch the optic. With a hemostat or tweezers, grip the folded tissue parallel to and near the fold. Wet the “brush” with acetone and shake off any excess liquid.
Blow off the dust. Place the brush on the optic surface, apply slight pressure with the hemostat, and slowly wipe straight across, from one edge of the optic surface to another.
The “Brush” Technique for Small- Diameter or Mounted Optics
You can use a modified “brush” technique for small-diameter or mounted optics. This technique is ideal for our Models 5511 and 552X polarizers, Models 554X wave plates, and Model 572X-H aspheric lenses.
For these optics with hard-to-reach edges, make a small brush by wrapping an optic tissue around the soft tip of a synthetic lowlint swab. In one motion, “paint” the optic perimeter and sweep across the center of the optic. Wiping in a continuous motion prevents drying marks.
The “Wipe” Technique (not recommended for metallic coatings) This method is useful for heavier cleaning of stubborn stains. Fold the lens tissue as described in the “brush” technique above, and grip it with your fingers instead of the hemostat.
Applying a uniform pressure on the optic edge, slowly wipe across the optic’s face.

Use the “wipe” technique to remove stubborn stains on more durable coatings.
The “Immersion” Technique For softer coatings, which damage more easily, we recommend using the “immersion” technique. Simply remove any dust from the optic and then immerse it in acetone. If the optic is very dirty, you can use an ultrasonic bath. Rinse and immerse the optic in fresh solvent a number of times until it’s clean. To dry the optic, carefully blow the solvent off from one direction to avoid leaving drying marks.
Once You Have Cleaned Your Optic Place the optic in the mount it will be used in or wrap it in lens tissue and place it in its container right away.

CLEANING PRODUCTS

There are a variety of cleaning products and cleaning methods to use depending upon the type of optic to be cleaned and the nature of the care needed, ranging from removing dust to smudges on the surface. Products such as Pick-Up Tools, Tweezers, Gloves, Compressed Air, Cotton-Tipped Swabs, Lens Tissue, Lens Cleaners, Reagent-Grade Isopropyl Alcohol, Reagent-Grade Acetone, and De-Ionized Water can be used to ensure a long product lifetime. Each type of cleaning product has its own unique benefit: Pick-Up tools and Tweezers are useful for holding optics in place while cleaning, Gloves provide a protective barrier to optics from any moisture or oils on your hands, Compressed Air effectively removes surface dust without directly contacting any coating an optic may have, Cotton-Tipped Swabs and Lens Tissue offer an effective means to wipe away any dirt without scratching an optic, and Lens Cleaners, Reagent-Grade Isopropyl Alcohol and Acetone, and De-Ionized Water each safely clean an optic.
An important point to stress is that you should NEVER clean plastic optics or optics in plastic housings with Acetone because it will damage the plastic. Therefore, if you have a plastic optic, then you should use Compressed Air, Reagent-Grade Alcohol, or De-ionized Water. If you are unsure about the type of optic that you have or the reactivity of your optical substrate or coating, then using De-Ionized Water and a little bit of dish soap is the safest way to make sure the optic is not damaged by harsh chemicals.

Want to see one of our Applications Engineers demonstrate how to clean optics? View our Cleaning Optics video for an instructional tutorial on properly cleaning optics.