APD120A2-M In Stock

The APD120A2/M offered by ThorLabs is a state-of-the-art Silicon Avalanche Photodetector (APD) designed to provide superior sensitivity and lower noise levels compared to standard PIN detectors. This makes it an ideal choice for low light detection applications such as spectroscopy, fluorescence measurements, laser radar, and optical rangefinders.

The APD120A2/M incorporates a high-sensitivity Si photodiode, which is paired with a custom-designed ultra-low noise transimpedance amplifier. This combination allows for the detection of optical signals ranging from DC to 50 MHz. Thanks to its exceptional sensitivity, the APD120A2/M can serve as a replacement for Photomultiplier Tubes (PMTs) in numerous applications. Unlike many PMTs, the APD120A2/M is impervious to damage from unwanted ambient light, providing an additional advantage.

To increase sensitivity, the APD120A2/M employs an internal gain mechanism. The diodes receive a high reverse bias voltage, generating a strong electric field. When light interacts with a material, the electric field created by it can accelerate electrons, leading to the creation of additional electrons through impact ionization. These secondary electrons generated from one incident photon are what create an electron-hole pair. The resulting electron avalanche can produce a gain factor of several hundred times, described by a multiplication factor, M. The M factor is a function of both the reverse bias voltage and temperature and generally increases with lower temperatures and higher reverse bias voltage.

With its slim line housing, the APD120A2/M offers a sleek design that is not only attractive but also convenient. Equipped with a removable threaded coupler that is compatible with any compatible 1” and ½” threaded accessories, this photodetector allows for the external optics, filters, apertures, or fiber adapters to be easily mounted. Moreover, the APD120A2/M has three tapped mounting holes that offer additional mounting options, providing maximum flexibility for any application. The APD120A2/M is powered by an external power supply, the LDS12B, which is connected via a PICO M8 power connector. With a power output of ±12VDC and 250 mA, this power supply is capable of providing a reliable and consistent power source for the user’s photodetector. To accommodate various input voltages, the APD120A2/M features a switch on the power supply that allows the user to select the appropriate input voltage.