Extended InGaAs Detector Now Available as Line Array
(PresseBox) (Olching, )For SWIR spectroscopy a new xInGaAs detector has been developed: The line sensor IG22 is manufactured by LASER COMPONENTS and has 256 pixels @ 30 μm x 250 μm each with a pitch of 50 μm. In cooled operation, the spectral range is covered up to 2.1 μm (20% point).
The sophisticated extended InGaAs has interesting advantages: The dark current in photodiodes depends on the bias voltage applied. Thus, voltage-free operation is ideal; realistically, however, the input offset of the amplifier acts as bias voltage. In the IG22 array, this undesired voltage is reset to zero after each readout.
The amplification can be finely adjusted at eight levels, individually per pixel. This is practical because the middle of the line is often illuminated more strongly than its edges. Thus, the optimal dynamic range per pixel can be utilized.
The array is designed with a high linearity - the aim is a value of 99.9%. The optimized thermal design consists of a two-stage Peltier element - so the array achieves a dT of 65 K (i.e., it can be cooled from room temperature to -40°C). Inaddition an anti-alias low-pass filter is integrated before the sample-and-hold circuit.
This array is equipped with all commercial standard features, such as correlated double sampling (CDS). Complete evaluation electronics are available with a USB interface.