These versatile and ultrasensitive detectors reach NEP levels surpassed only by PMTs. The linearity range is unmatched by any other detector type. They have excellent long term stability, especially the UV enhanced models. These withstand high intermittent and cumulative levels of UV without significant change of response. The TE stabilized units overcome the small temperature dependence of silicon responsivity for even better performance. This is especially critical in the near infrared spectral region, >1 µm, in the vicinity of the band gap.
Lowest measurable powers of Silicon Based Detectors operated by Merlin™.
Cooled or Room Temperature Photovoltaic Mode Detectors
These photovoltaic, unbiased mode detectors provide the lowest noise and highest linearity operation. We offer:
- 5 mm diameter area, single stage TE cooled/stabilized detectors
- 10 mm2 area, room temperature detectors
Switch selectable transimpedance gain and bandwidth control are provided by the built-in amplifiers.
Measurable Power
The built-in transimpedance amplifiers allow gains between 104 V/A and 109 V/A to match the output of the detectors to the input range of MerlinTM, 0.15 µV to 4 V, RMS.
The phase sensitive detection of MerlinTM allows measurement of low signal power even in the presence of background radiation. We have used the 10 mm2 detectors to measure 200 fW at 700 nm, at signal to noise ratios of better than 2:1.
Calibration
We offer calibrated and standard versions of these detectors. The standard models are shipped with a single point calibration at 633 nm. You can enter that value into Merlin™ for a calibrated measurement. Because of the spectral variation in response, the displayed value is only correct for 633 nm. You can approximately correct the power reading using relative responsivity curves, if you know the spectral content of the incident radiation. For absolute measurement at different wavelengths, choose a calibrated detector.
Detector Systems
We offer various silicon detector packages for the Oriel Merlin™ Digital Lock-in; each package includes:
- Silicon detector element
- Detector housing with built-in preamplifier
- All necessary interconnecting cables
To complete the system, you will also need to order:
- Model 77055 Cooler Controller for the cooled systems
- Merlin™ Control Unit
- Chopper
