Photodetector Characterization Setup


Temperature ranges from 0 to 150°C
Displays Conductivity with Temperature


No detector has a constant spectral responsivity under all conditions of use. For instance, the responsivity of photodiode detectors falls off above a certain incident power level due to saturation effects. Full evaluation of a detector requires characterisation of such effects. This information allows the identification of the detector with the best performance for a particular application. Also, a detector to be used for calibration purposes should be fully characterised in order to evaluate the uncertainty of such calibrations.

In all cases the detector under test is compared with a standard detector of known spectral responsivity / quantum efficiency.

300F Monochromator is used to select a narrow wavelength band from a broad band quartz halogen lamp. Wavelength range of monochromator is between 200 – 2000 nm. The wavelength can readily be tuned continuously allowing measurement of spectral responsivity across the wavelength range for which the detector is used


    Optical path :     Czerny-Turner configuration
    Scanning range :     200 – 2000 nm (UV requires Special Lamp)
System comes with Quartz Halogen Lamp which Wavelength Range is 350 – 2000 nm
for UV range less than 350 nm special lamp is required
    Resolution :     0.1nm (@ 546 nm, 10 μm slit width)
    Wavelength accuracy :     ≤ 0.2 nm
    Wavelength repeatability :     ≤ 0.1 nm
    Incident power levels :     10-10 – 10-3 W range
    Laser Wavelength :     532 nm
    Chopper frequency :     400 Hz
    Maximum beam :     15 x 10 mm
    Voltage range :     1 to -1 V
    Resolution :     5 mV
    Current range :     0.1 uA to 0.75 A

HOLMARC Model: HO-PDC-01 designed for characterisation / measurement of the following detector parameters:

Linearity range : This is the range of incident radiant power levels over which the detector output varies linearly with incident power. (Laser-based methods is used for measuring saturation threshold of a detector).

Spatial non-uniformity of response : The variation of responsivity across the active area of a detector is determined by scanning a small spot of radiation at a selected wavelength over the surface.

Noise Equivalent Power (NEP) : the incident radiant power at a specific wavelength and modulation frequency necessary to produce a signal-tonoise ratio of 1 at the detector output.

Temperature coefficient of response : the variation of responsivity with temperature

Detector shunt resistance : the slope of the current-voltage curve of a photovoltaic detector at zero-volt bias.