Available in multiple material types and surface treatments to allow for optimal transmission of specified wavelengths.
Optical disk used for viewing a process is commercial grade borosilicate glass such as 7056 or Kodial. For optical-critical applications, fused silica, quartz, sapphire, germanium are available. Choose optical material that has a high transmission at the wavelength of interest.
Kodial viewport can withstand repeated bakeout cycle to 350° C. However, to avoid thermal stress, the heating rate should not exceed 2 deg. per minute. Finger-tight the bolts; use cross-flange tightening pattern, and never rotate any particular bolt more than 1/8 turn at a time.
Transmission chart
Laser Transmission chart