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| Home > IR & THz Long Pass Filters |
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| IR & THz Long Pass Filters |
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 Back to Product Description and Features of IR & THz Long Pass Filters |
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| Long wave pass filters |
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| Scattering Design |
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| In scattering filters the filtering occurs due to the wavelength-selective scattering of light.
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| The rejection level of such filters depends on the detector to filter separation, as shown in the plot.
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| Lake Shore filter design insures uniform and efficient scattering with nearly Gaussian angular distribution with >90° width.
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| Cleaning and Handling of Filters |
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Lake Shore IR filters have excellent thermal and mechanical properties — even at cryogenic and elevated temperatures. They are carefully packaged and inspected before shipping and are shipped in protective containers. No additional cleaning is required after shipment. Upon visual inspection, some areas of the filter may not be visually uniform. Filter performance is not compromised by this non-uniformity. |
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IR filters are fragile, and unnecessary handling should be avoided to reduce the risk of damage. When handling filters, care should be taken to ensure that the environment is as clean as possible, and the filters should only be handled by the edges. Avoid touching the flat optic area, even during cleaning, as it could lead to degradation of filter performance. Never wipe or abrade the filter with anything during handling or cleaning, as this could cause permanent damage. |
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| If a filter has been contaminated and requires cleaning, rinse with ultra-pure isopropanol (IPA) and quickly dry with a stream of nitrogen gas. Using lower purity IPA or other solvents is not recommended. To avoid drying stains, DO NOT let the optic slow or air dry. If the filter is still dirty after following this procedure, it can be cleaned using following steps: |
- Immerse in a warm solution of 66% concentrated sulfuric acid/33% hydrogen peroxide (piranha) for 15 min
- Rinse in de-ionized water for 1 min
- Immerse in 10% hydrofluoric acid
- Rinse in de-ionized water for 1 min
- Rinse with ultra-pure IPA
- Blow dry with nitrogen gas
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| Note: Depending on the severity of contamination, the filter may be permanently damaged. |
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| If you have any questions or require any additional information, please contact a Lake Shore engineer at irfilters@lakeshore.com |
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| Spectral Scans |
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| Spectral scans will be shipped with each filter. If there are a number of nearly identical filters purchased and shipped together, one spectral scan for the lot will be shipped. Standard spectral measurements will be performed at room temperature at near-normal incidence. Spectral evaluation at 4.2 K and 77 K can be provided for an additional cost. |
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| Click here for IR & THz Band Pass Filters |
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| Back to Product Description and Features of IR & THz Long Pass Filters |
Contact an expert on IR Filters
Tel: (614) 891-2243 × 201
email: irfilters@lakeshore.com |
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