Polychromators Specifications

Model GAPB 1064-4-1K
1064 - laser wavelength in nanometers
4 - number of channels
1K - APD load resistance in ohms

The Model GAPB 1064-4-1K polychromator has been optimized for Thomson scattering measurements with Nd:YAG lasers. It can be easily modified for other lasers and/or other applications using different interference filters and detectors.

Mechanical Specifications
Overall dimensions: 8 cm x 25 cm x 75 cm Weight: approximately 3.5 kg
Spectral channels: 4 (space for 4 more) Temperature stability: water cooled
Iinput fiber adjustment: ± 1.6 mm in x, y, z Detector adjustment: ± 1.4 mm in x, y, z
Detector monitoring: filter bypass*
Optical Specifications
Input fiber diameter: 2.8 mm nominal Numerical aperture: 0.28
Incident angle of light: 4o at filter Full cone angle of light: 4o at filter
Image size at detector: 2.0 mm nominal Optics: BK7, broadband AR coated
Interference Filters
Diameter: 32 mm Clear aperture: 27 mm
Peak transmission: 60 - 80% (typical) Transmission@1064.3 nm: <10-5 (except laser filter)
Transmission out of band: < 10-4 @ 0.2 - 1.2 µ Reflection out of band: >95% @ 0.6 - 1.07 µ
APDs
Detector: EGG C30956E Diameter: 3.0 mm
HV bias: 250 - 400 V (typical) Avalanche gain: 50 - 100 (typical)
Quantum eff. @ 1060 nm: approximately 40% Quantum eff. @ 900 nm: approximately 80%
Noise enhancement factor: 3 (typical)
Amplifier
Input power: ± 8 V @ 45 - 100 mA APD load resistor: 1 kohm
Output connector: 7 pin coax
Pulsed Channel Background Channel
Gain: 40 Variable gain: 4, 8, 20, 40
Frequency response: 5 to 25 MHz Frequency response: DC to 15 MHz
Output impedance: 50 ohms Output impedance: 50 ohms
Noise @ 75 ns gate: 80 photoelectrons Gain selection: TTL inputs
* For performance monitoring, each detector has an SMA fiber optic connector and lens so that light may be introduced via a fiber optic, bypassing the interference filter.