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large detector area free space optical receiver by new focus
Optical Receiver, Large Area, 5.8 mm Silicon Detector, 190-1100 nm
In Stock
In Stock
Photoreceiver, Large Area, 5.0 mm Germanium Detector, 800-1750 nm
In Stock
In Stock



High Speed Receiver Physics

With the advancement of high-transmission-rate systems and short-pulse lasers, many applications now require high time-resolution or equivalently, high frequency-bandwidth optical detection. High-speed photoreceivers are critical for the measurement of the frequency and/or time response of optical systems. In the optical domain, this can include measuring the pulses of mode-locked laser systems, detecting the data stream of a frequency-multiplexed communication system, or providing increased resolution in dynamic, pump-probe spectroscopy. The minimum rise time for high-speed photoreceivers is less than 10 ps. Consequently, for optical signals with faster responses, optical gating techniques are required. In the frequency domain, applications for high-speed photoreceivers include laser heterodyning experiments and millimeter-wave signal generation. The maximum frequency bandwidths for such detectors can exceed 50 GHz in well-designed devices.

Based on the discussion above, diffusion of carriers to the depletion region is a relatively slow process in reverse biased p-n junctions that could serve to limit the response time of a photoreceiver. To minimize this effect, a p-i-n photodiode is typically utilized where an un-doped intrinsic layer is sandwiched between the p and n layers in a p-n junction (see above figure). This structure effectively widens the depletion layer. This results in a greater proportion of the generated current being carried by the faster drift process instead of diffusion. The increased depletion width also allows for a reduction in the RC time constant(via a decreased junction capacitance) and increased area for capturing light. The p-i-n device structure is ubiquitous in high-speed photoreceivers and enables fast rise times and large bandwidths. However, the final measured optical signal will be as slow as the slowest component of a detection system even if a sufficiently fast photoreceiver is employed. Therefore, care should be taken when choosing connectors, cables, an oscilloscope, and a spectrum analyzer to measure a fast optical signal.

Silicon and Germanium Diode Versions

Utilizing both UV-Extended Silicon and Germanium, there is a model covering wavelengths from 190 to 1750 nm for your application.

Adjustable Gain Settings

The three-setting gain adjustment allows you to keep your signal from going off scale while you’re adjusting your experiment or measurement. You can choose a 50-Ω or 10-kΩ load resistor, or you can select the open-circuit setting and provide whatever load resistor you like.

Compact Housing

The compact housing lets you slide the photoreceiver in wherever you need to quickly check your signal, even between closely spaced optics. Since all switches and connectors are located on the top of the housing, you won’t have to worry about access or about cables that drag on the table and block your beam.

Battery Powered

These photoreceivers are battery powered so you’ll need only a single coaxial cable to connect the photodetector to other instruments. To ensure long battery life, we build these photoreceivers using amplifiers with low-current draws. If you’re unsure about the battery status, the built-in battery check can tell you instantly whether or not the battery is good.