Hermetically sealed in a 4-pin, TO-5 package that is grounded for shielding purposes, the Model 61099 hybrid device combines a photodiode with a low-noise operational amplifier to provide high sensitivity with low noise measurement of light. Capable of operating over a temperature range of 0°C to 70°C, the transimpedance amplifier device also has a 500-Megaohms gain resistor and is used in applications such as industrial controls, pollution monitoring, and light measurement.