Our Models 2151 and 2153 photoreceivers are ideal for ultra-low-light-level detection. When used with a chopper and a lock-in amplifier, these photoreceivers can easily achieve sensitivity levels in the femtowatt range.

These photoreceivers provide amazing amounts of gain (up to 2x1011 V/W) and yet are easy to use, making the most difficult spectroscopy or fluorescence experiment a snap. They’re powered by a single 9-V battery, and don’t require cooling or high-voltage power supplies. They’re sensitive from the UV all the way to the IR, giving you the flexibility to work wherever you get the most signal. Their 1-mm photodetector diameter even makes alignment easy.

The incredibly high-gain and low-noise performance of these photoreceivers is achieved by careful selection of the amplifier-resistor pair. A large feedback resistor provides the high-gain values, while an ultraquiet amplifier keeps noise to a minimum. Since the unit is battery powered, you’ll need only a single coaxial cable to connect the photodetector to other instruments. This eliminates ground loops, the most common source of noise. A non-conductive pad electrically isolates the case from the table, further eliminating noise pickup.

You can easily switch among the three fixed gain settings of 2x1011 (AC), 2x1010 (AC), and 2x1010 (DC) V/A. The two AC settings have a low-frequency roll-off at 30 Hz and eliminate DC drifts. To filter out unwanted background signals, you can also mount spike or band-pass filters directly on the photodetector with the filter-holder accessory.