Design of multi-wavelength optical power meter using feedback resistor combination

Optical power is one of the important parameters in optics. Optical power is used to determine losses that occur along the optic link. Optical power is also needed in the designing optical fiber sensors. In this research, design of signal-conditioning-circuit and optical-power-measurements characterization for laser at wavelength 1310 nm and 1552 nm have been conducted. This device works as an optical power meter. It uses 6 units of resistances (100 Ω, 1k Ω, 10k Ω, 100k Ω, 1M Ω and 10M Ω) as feedback of transimpedance amplifier. These resistors are connected in parallel and combined to expand the measurement range of optical power. The obtained data were compared and validated with Anritsu ML9002A OPM. The result was 5 different optical power measurement regions for each wavelength from -5 dBm to -45 dBm. This range can be expanded using analytical approach to obtain a wider dynamic range.