Position sensitive detectors. Spatially-resolved photodiodes measure the position of a light spot. The bandwidth and resolution of so-called position sensitive detectors (PSDs) are unmatched.
SPC PSDs are position sensitive detectors with integrated signal processing circuitry.
To simplify the work for a user, the signal processing circuit is already connected to the position sensitive SPC detectors from SiTek.
It contains four individual transimpedance preamplifiers (two for the X-axis and two for the Y-axis) as well as sum and difference amplifiers for each axis, both with inputs for an offset adjustment. The PSD currents are converted into bipolar voltages that represent the position and intensity of the center of a laser spot with high resolution on the sensitive surface.
The circuit is mounted on a 20.5 mm x 20.5 mm² large ceramic substrate using a thick film technique with laser trimmed resistance. It is charged with ±15 V and emits a maximum output voltage of ±12 V. The 3 dB bandwidth averages 400 Hz at a rise time of 13 V/µs.
The signal processing circuit is available in a compact design together with two dimensional Si PSDs, the 2L 10 (10 x 10 mm) and the 2L4 (4 x 4 mm), as well as with the one dimensional Si PSD, the 1L5 (5 x 1 mm).
The circuit can also be combined with all other SiTek PSDs.
SPC PSD Available with Evaluation Board
The evaluation board makes the handling of PSDs even easier. The detector is mounted on a small PCB that can be fixed to an optical bench. All incoming and outgoing signals are connected with a 14 pol connector.