These direct bandgap semiconductor devices have excellent speed of response and linearity. They are a little bit noisier than silicon detectors, due to the smaller band gap, and therefore we offer one with two-stage TE cooling for radiometric applications. The 1.3 µm and 1.55 µm wavelengths, lie within the 0.8 to 1.7 µm detection range. Transmission and loss measurements can be done most accurately with these extremely stable and sensitive detectors.
Fig. 1 Measurable power of the TE cooled 70348 detector, operated by Merlin™.
Fig. 2 Relative responsivity of the 70348 InGaAs detector.
Room Temperature vs Cooled
We achieve excellent stability of response with the TE cooled detectors as a result of the inherent qualities of the diode and thermal stabilization at temperatures down to -20°C. The room temperature detectors will serve you well if you don't work too close to the extremes of their spectral range, especially at 1.7 µm.
Calibration
The stability and linearity of response of our InGaAs detectors makes them excellent candidates for calibrated measurements. We ship the standard models with a single point calibration at 1.55 µm. Use the typical responsivity curve shown in Fig. 2 to approximate responsivity at other wavelengths. For highest accuracy, we offer calibrated models with NIST traceable calibrated responsivity factors for the 0.8 to 1.7 µm range.
Detector Systems
Each InGaAs detector package includes:
- InGAs detector element
- Detector housing with built-in preamplifier
- All necessary interconnecting cables
You will also need to order:
- Model 77055 Cooler Controller for the cooled systems
- Merlin™ Control Unit
- Optical Chopper
