PDA50B In Stock

The PDA50B by ThorLabs is a high-performance, germanium (Ge) switchable-gain detector designed to detect light signals in the 800 to 1800 nm range. This amplified detector features a thin profile that allows easy access to light paths in limited spaces. The PDA50B is equipped with connections and controls that are positioned perpendicular to the light paths for added convenience.

The PDA50B features a low-noise transimpedance or voltage amplifier that is capable of driving 50 Ω loads. It is housed in a durable casing that has a removable SM1-threaded cap, allowing for the zero input calibration sensor to be covered. The SM05 threads make it easy to mount external optics, fibers and apertures, while the two 8-32 tapped mountain holes, internal SM1-threaded adapter ring, and switchable power supply enable compatibility with fiber coupling adapters and easy incorporation into lens tube or cage system setups. Though the PDA50B can be set up in a number of ways, it is recommended that the device be always mounted and secured for the best possible operation.

The PDA50B stands out for its ability to accurately measure both pulsed and CW (continuous wave) light sources. This device uses a reverse-biased PIN photodiode along with a switchable gain transimpedance amplifier. The entire package is also encased in strong housing for added protection. The low noise, low offset, high gain transimpedance amplifier allows for gain adjustment over a 70dB range. By rotating the gain control knob on the top of the unit, the gain can be adjusted into 8 different positions incremented in 10dB steps. As gain increases, bandwidth decreases, ensuring accurate readings.

The PDA50B also features controlled dark current leakage, which flows when a bias voltage is applied to a photodiode. Because it is a germanium device, it has higher dark currents compared to silicon devices, but the PDA50B is still capable of controlling the leakage current for accurate measurements. It has a sensitivity range of 900 - 1600 nm, is low speed, low cost, has compact package dimensions of 2.76" x 2.06" x 0.88" and a weight of 0.15 lbs.