Patent ID: 7842910

Claim:
A host board comprising: an optical module including: a light emitting element, a light receiving element, and a memory circuit that stores property data associated with a property of the light emitting element and the light receiving element, the property data including a current-to-optical conversion efficiency, a light emitting critical value, and temperature variation properties for the light emitting element, and an optical-to-current conversion efficiency, a breakdown voltage, and temperature variation properties for the light receiving element; and a first control circuit that controls the light emitting element and the light receiving element based on the property data when the optical module is mounted on the host board, wherein the first control circuit is to provide a modulation current and a bias current to the light emitting element, based on the current-to-optical conversion efficiency, the light emitting critical value, and the temperature variation properties for the light emitting element stored in the memory circuit, and also based on a desired optical output power and a desired extinction ratio of the light emitting element, wherein the first control circuit is further to generate a reverse bias voltage of the light receiving element based on the optical-to-current conversion efficiency, the breakdown voltage, and the temperature variation properties for the light receiving element stored in the memory circuit, wherein the memory circuit, the light emitting element, and the light receiving element are all mounted on and are part of the optical module, whereas the first control circuit is not part of the optical module but rather is connected to the optical module on the host board, and wherein no adjustment of the optical module is necessary for the optical module to function.