Long pass filters

The long pass absorption filter is designed to remove short wavelength light (e.g. residual pump light) from a longer wavelength laser signal.
Our long pass filters use an epitaxial semiconductor absorber layer on a semi-insulating GaAs crystal. This wafer material can be diced in small rectangular chips according to the customer needs. The short wavelength light is absorbed in the filter and subsequently converted into heat. For heat removal an appropriate metal mount as heatsink has to be used.

We provide unmounted long pass filters with a standard substrate thickness of 625 µm.

Available chip areas:

• 5.0 mm x 5.0 mm
• 4.0 mm x 4.0 mm
• 2.0 mm x 2.0 mm
• custom dimensions on request
• 1/2" or 1" copper heat sink for 5.0 mm x 5.0 mm filters