Suboptimal Dual Control Algorithms for Discrete-time Stochastic Systems under Input Constraint

A receptacle-type optical module has a semiconductor laser device, and a glass rod arranged to be contacted tightly with an optical fiber ferrule to guide light emitted from the semiconductor laser device to an optical fiber. A marker is formed on the physical contact face of the glass rod to position the optical axis of the semiconductor laser device. The semiconductor laser device is caused to emit light, and at the same time, the marker image on the physical contact face and the image of the light emitted from the semiconductor laser device are picked up with an infrared camera and subjected to two-dimensional image processing by an image processing unit, thereby detecting the positional shift of the semiconductor laser device from the desired position. A fine adjustment stage is driven in the direction perpendicular to the optical axis of the semiconductor laser device on the basis of the information of the positional shift to position the semiconductor laser device.