SWIR deeply cooled camera

30 May 2019

Photonic Science is releasing a new compact SWIR InGaAs camera with cooling down to -50°C allowing long exposures for semiconductor failure analysis, small animal imaging and astronomy applications.

The camera incorporates a 640 x 512 VGA high grade sensor, 15 micron pixels and quantum efficiency response >70% at the silicon emission peak and >80% at 1550nm.

The sensor supports 3 gain modes.

The high gain mode delivers less than 30 electrons Read Out Noise (RON) with a Full Well Capacity (FWC) in excess of 22,000 electrons. This mode is used under light starved conditions with signal to noise ratio not exceeding 700:1.

The medium gain mode delivers 50 electrons RON with an FWC in excess of 100,000 electrons. This mode allows detection of very low emission signals whilst maintaining 2,000:1 intra scene dynamic range in a single image.

The low gain mode delivers 400-450 electrons RON with 1.2 to 1.4 Million electrons FWC. This mode is used when the largest dynamic range, up to 3,000:1 needs to be achieved.

The cooling reduces dark current to typical values of 750 electrons / pixel / second, which in mid gain mode allows 1 minute exposures while remaining under half saturation. Signal to noise ratio in excess of 200:1 remains achievable.

A control loop algorithm maintains a stabilised temperature within +/-0.5°C, which ensures reliable in camera corrections routines. Bad pixels, offset, gain linearization and dark current in camera corrections deliver precise and reproducible metrology measurements.

With 4-tap low noise electronics the camera is capable of streaming data at up to 174 frames per second (fps) through a Gigabit Ethernet Vision (GEV) compliant interface. Faster frame rates can be achieved using a cropped Region of Interest (ROI) on the sensor. Used in line mode for spectroscopy acquisition, the sensor will achieve 7,200 fps @ 640 x 4 ROI and a centred 320 x 256 ROI will achieve 570 fps. This high frame rate enables integration of multiple images without any dead period. This is an essential feature when sampling long exposures using the non-destructive mode on the camera.

The GEV compliant interface allows either native uncorrected or corrected data using a Windows based or Linux based SDK. The camera’s compact size is just, 70mm (width) x 70mm (Height) x 100mm (length) and has a power consumption of 20W.