With clean, fast impulse responses with minimal ringing, these photodetectors are ideal for time-domain applications in high-speed digital fiber-optic communications systems including BER testing, characterizing modulators and other components, and short-pulsed-laser measurements. For frequency-domain applications, please see our 45 GHz or 25 GHz Fiber-Optic Detectors which provide a flat frequency response over wide bandwidths.

Our Time Domain Photodetectors utilize a InGaAs diode providing wavelength coverage from 500 to 1630 nm for single mode and 850 to 1630 nm for multimode fiber.

Because of their optical-fiber input, these photodetectors can be connected directly to electronic instruments, eliminating the need for expensive and lossy high-frequency microwave cables. For your convenience, these photodetectors are internally terminated at 50 Ω, so they don’t require a 6-dB attenuator to achieve a good impedance match with SDH and SONET filters or when used with microwave filters.

• Direct temporal proile measurements of nsec pulsed lasers for marking and machining applications 
• Characterizing the frequency response of pulsed lasers, modulators & transmitters
• Microwave generation - heterodyne experiments
• Characterizing pulse propagation through dispersive optical systems

The compact, self-contained packaging of these photodetectors powered by a user-replaceable 9-V battery makes them useful in laboratory investigations of data communications systems. The photodiode bias circuit and battery are built into the RF-shielded case, reducing the risk of damage from excessive voltage or rough handling, and eliminating the need for expensive bias tees. All these photodetectors also come equipped with a DC-bias monitor that has a transimpedance gain of 1 mV/µA in a 50-kHz bandwidth.