Automatic Calibration System for a Laser Power Meter

A microprocessor-based calibration system for a CW laser power meter has been developed. The system consists of an isothermal calorimeter with a thermopile unit, an electrical, and an optical subsystem. Temperature control of the thermopile unit is achieved through a digital technique. The calibration of a power meter is performed using the effective efficiency of the unit as measured by a calorimeter. From error analyses, an overall accuracy has been obtained as ±1 percent in root mean square for a power level of 1 ~ 200 mW.