This is an 0-24 VDC Ideal Spectroscopy photodiode variable bias module with included 24V, 2A DC power supply. This module is used to apply a DC bias to a compatible photodiode for greater sensitivity and linearity, and more rapid time response. The bias voltage is adjusted via a rotatable knob on the side of the bias module. The photodiode must be attached via the input female BNC connector. The output is monitored by connection to the output female BNC connector. Optionally, the 0-24 VDC bias voltage may be monitored via connection to the bias monitor female BNC connector for precise voltage control. Photodiodes are light detectors used in many spectroscopy applications. An unbiased photodiode acts as a photovoltaic device, which generates a single electron of current per excitation event. The photodiode output may be monitored either by measuring the current produced or by applying a resistance to the photodiode output and measuring the voltage build up as current is impeded. Photovoltaic operation is the simplest mode of action and has minimal dark current. Unfortunately it suffers from low amplification, nonlinear voltage response over large dynamic ranges, and slow response due to a short depetion width and large junction capacitance. Unbiased photodiodes are best for slow or very low light applications.

This is a mounted large-area silicon photodiode. It is best used for large visible or near infrared beams or spots in the range of 350-1100 nm. The photodiode is anode grounded and is equipped with a female BNC electrical connection for easy compatibility with existing lab systems. This mounted photodiode is compatible with Ideal Spectroscopy's photodiode variable bias module which provides a bias of 0-24 VDC for a faster, more linear, amplified response. The anodized aluminum photodiode housing has several mounting features. The front face is equiped with an internal SM1 thread that can connect to a 1" diameter lens tube or other standard optical aparatus. The back of the photodiode housing has an external SM1 thread for installation into threaded optical mounts for 1" OD optics and devices. There is a also a smooth 1" OD section for mounting into kinematic mounts with a 1" ID smooth bore. A 8-32 threaded hole on the base of the mount allows for direct connection to standard optical posts.