• Central Wavelength: 632.8 ± 2 nm
• Ø1" Mounted Filters
• Edge-Scribed for Superb Long-Term Stability
• Typical Transmission Plots Available for Every Filter
• Laser Line Filters for Popular Diode and Nd:YAG Laser Lines

This Thorlabs' bandpass filter provides one of the simplest and most economical ways to transmit a well-defined wavelength band of light, while rejecting other unwanted radiation. The design is essentially that of a thin film Fabry-Perot Interferometer formed by vacuum deposition techniques and consists of two reflecting stacks, separated by an even-order spacer layer. These reflecting stacks are constructed from alternating layers of high and low refractive index materials, which can have a reflectance in excess of 99.99%. By varying the thickness of the spacer layer and/or the number of reflecting layers, the central wavelength and bandwidth of the filter can be altered. Because of the Fabry-Perot design, these filters are designed to be used at a 0° angle of incidence (AOI). The transmission band will be shifted in wavelength and may be reduced when used with other AOIs.

This type of filter displays very high transmission in the bandpass region, but the spectral range of blocked light on either side of the bandpass region is narrow. To compensate for this, an additional blocking component is added, which is either an all dielectric or a metal-dielectric depending on the requirements of the filter. Although this additional blocking component will eliminate any unwanted out-of-band radiation, it also reduces the filter's overall transmission throughput.

• Out of Band Transmission: <0.01%
• Housing Diameter: 1"
• Housing Diameter Tolerance: +0.0 / -0.2 mm
• Clear Aperture: Ø21 mm (Min)
• Thickness: <6.3 mm
• Surface/Coating Quality: 80-50 Scratch-Dig
• Edge Treatment: Mounted in Black Anodized Aluminum Ring
• Substrates: Schott Borofloat and Soda Lime
• Optimum Operating Temperature: 23 °C
• Operating Temperature: -50 to 80 °C
• CWL: 632.8 ± 2 nm
• FWHM: 10 ± 2 nm
• T (Min): 0.7
• Blocking: 200 - 1150 nm