PDA400 In Stock

The ThorLabs PDA400 is an amplified InGaAs detector that is specifically designed for precise and reliable light signal detection from DC to 10 MHz. With its advanced features and versatile design, the PDA400 is an ideal choice for a wide range of applications where accurate light detection is crucial. One of the key features of the PDA400 is its five-position rotary switch, which allows users to easily adjust the gain in 10 dB increments. This feature provides enhanced flexibility and control over the detection process, ensuring optimal results in various operating conditions. The buffered output of the PDA400 is capable of driving a load impedance of 50Ω of up to 5 volts, providing reliable performance in demanding environments.

The PDA400 also features a threaded coupler that removeable and compatible with threaded accessories that are 1” in size. This convenient design allows for easy mounting of compatible cage assembly accessories, apertures, light filters, and external optics, making it a versatile solution for different experimental setups. Installation and operation of the PDA400 are made simple with its 8-32 tapped mounting hole, 0.25” mounting depth, and included 120VAC power AC/DC supply. The gain adjustment is easily done using a small slotted screwdriver through the labeled GAIN access hole on the rear panel, with the gain set to 0dB when the switch is turned counterclockwise. Each clockwise click of the switch increases the gain by 10 dB, allowing for precise gain control without applying excessive force.

To ensure accurate and reliable results, it is recommended to adjust the gain of the PDA400 so that the measured signal level is under 10 volts to avoid saturation. If needed, external neutral density filters can be used to reduce the input light level. It should be noted that the bandwidth of the PDA400 may decrease with increased gain settings, as is common with amplifier circuits. The PDA400 is designed with accessibility in mind, featuring a front surface diode that extends outside of the housing for easy access. However, when using fiber adapters, caution should be taken to avoid crashing the fiber ferrule into the detector, as it may cause damage to the diode and/or the fiber. To easily solve this issue, one can insert a compatible retaining ring into the 1" threaded coupler prior to putting in the fiber adapter.