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BATOP Logo Transmittive long pass filters

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

 Au mirrors

Long pass filter with cut-off wavelength 900 nm from stock

LPF-900-5x5


• Long Pass Filter 900 nm on GaAs substrate
• stopband λ < 880 nm
• passband λ > 950 nm
• Chip area: 5 mm x 5 mm
• Chip thickness: 625 µm
Data sheet (pdf)
Quote request
• Price: 70.- €/pc

LPF-900-4x4


• Long Pass Filter 900 nm on GaAs substrate
• stopband λ < 880 nm
• passband λ > 950 nm
• Chip area: 4 mm x 4 mm
• Chip thickness: 625 µm
Data sheet (pdf)
Quote request
• Price: 60.- €/pc

LPF-900-2x2


• Long Pass Filter 900 nm on GaAs substrate
• stopband λ < 880 nm
• passband λ > 950 nm
• Chip area: 2 mm x 2 mm
• Chip thickness: 625 µm
Data sheet (pdf)
Quote request
• Price: 50.- €/pc

5 mm x 5 mm filter glued on copper heat sink

LPF-900-5x5-12.7g-c


• Long Pass Filter 900 nm on 1/2" copper heat sink
• Chip area 5 mm x 5 mm
• Heat sink outer diameter 12.7 mm
• Heat sink with center hole 4mm diameter
• Mounting method: gluing
Data sheet (pdf)
Quote request
• Price: 200.- €/pc

LPF-900-5x5-25.4g-c


• Long Pass Filter 900 nm on 1" copper heat sink
• Chip area 5 mm x 5 mm
• Heat sink outer diameter 25.4 mm
• Heat sink with center hole 4mm diameter
• Mounting method: gluing
Data sheet (pdf)
Quote request
• Price: 200.- €/pc