Photodetector designs for low-noise, broadband, and high-power applications

We present design and performance details of three photodetector circuits that have been developed in the authors laboratory over the past eight years. These detectors have been optimized to meet the unique demands of experiments such as high power, high sensitivity interferometry, nonlinear optics, and laser noise measurements. The circuits are: a low-noise dc coupled (dc 20 MHz) general purpose detector, a low-noise broadband (15–1100 MHz) detector capable of detecting 10 mW of light, and a high-power large dynamic range detector (30 kHz–60 MHz) capable of detecting up to 100 mW of light. We present bandwidth dynamic range and noise performance details for all three designs. In addition, we present detailed circuit schematics along with design and construction guidelines to enable assembly and use of these designs.