Used Optical Power Sensor Modules for Sale

An optical power sensor (also called a detector head or sensor module) is a pluggable unit that contains the photodetector, transimpedance amplifier, and wavelength-correction EEPROM. It slots into a mainframe instrument — like the Agilent 8163/8164 or the Newport 2832-C — which provides the display, USB interface, and measurement firmware. An optical power meter is a complete, standalone handheld or benchtop unit with the detector built in. Sensor modules are used in modular platforms where you need to swap detectors for different wavelength ranges or power levels without replacing the whole instrument.

The 8163A, 8163B, 8164A, and 8164B mainframes all use the same sensor module interface. Compatible power sensor modules include the 81618A (single-channel InGaAs, −75 to +10 dBm, 950–1700 nm), 81619A (high-power InGaAs, −10 to +27 dBm for EDFA output), 81634B (dual-channel InGaAs), 81635A (dual-channel, 950–1650 nm), 81636B (high-power dual-channel), and older 81521B/81522B models. The 8164 is a dual-slot mainframe and accepts two modules simultaneously for simultaneous two-channel measurement.

InGaAs (Indium Gallium Arsenide) detectors cover 900–1700 nm with low noise floor (enabling −75 dBm sensitivity on the best modules) and high linearity. They are the correct choice for all telecom wavelengths: 1310 nm, 1490 nm, 1550 nm, 1625 nm. Germanium (Ge) detectors cover 780–1800 nm with a slightly higher noise floor and less uniformity — they are adequate for high-power measurements where noise is not the limiting factor. For anything in the C or L band, choose InGaAs. Si detectors handle visible to 1100 nm — not useful for singlemode telecom.

The only way to know is calibration against a NIST-traceable reference standard. A sensor with a calibration certificate that shows measured data (not just a pass/fail stamp) lets you see the actual deviation at each wavelength and power level. Sensors that have been operated near their maximum power input — repeatedly measuring EDFA outputs at +10 dBm when the rated maximum is +10 dBm — degrade fastest. When buying used, request the calibration history or budget for a post-purchase recalibration before putting it in a measurement-critical application.

Yes, with limitations. The most common failures are connector damage (the 2.5 mm ferrule adapter scratches the detector window when a dirty fiber is inserted under force) and EEPROM corruption that makes the mainframe not recognize the module. Detector replacement is possible on some modules — the InGaAs chip is a separate component — but the replacement must be characterized and a new EEPROM table written. We evaluate and repair sensor modules before sale, and accept warranty returns on repaired modules.

It depends on the module. Standard InGaAs modules like the Agilent 81618A measure from −75 dBm up to +10 dBm across a 85 dB dynamic range. High-power modules like the 81619A measure −10 dBm to +27 dBm — used after EDFAs and optical amplifiers where output power exceeds what a standard detector can accept. Exceeding the upper limit permanently damages the InGaAs layer; always check the module maximum before connecting an EDFA output.

InGaAs sensors work at 850 nm but with degraded responsivity compared to their peak at 1550 nm. Silicon detectors are optimized for 850 nm multimode measurements and give better accuracy at that wavelength. If you are doing multimode fiber certification at 850 nm and 1300 nm on a benchtop platform, check whether the platform supports an Si sensor module or whether you need a separate 850 nm-optimized handheld meter.

Aumictech Labs calibrates and repairs optical power sensor modules at our Pleasant Grove, UT facility. We issue NIST-traceable calibration certificates with measured data at each wavelength (850 nm, 1310 nm, 1490 nm, 1550 nm, 1625 nm). Common repairs: detector connector replacement, EEPROM reprogram for unrecognized modules, linearity correction after overpower events. Free evaluation. Flat-rate pricing. Instruments accepted from anywhere in the United States.