Hybrid surface emitting laser and detector

A hybrid laser and photodetector device mounted on a top surface of a silicon semiconductor chip for use in a holographic optical head, comprising:

• a gallium arsenide surface emitting semiconductor laser mounted on said top surface of said semiconductor chip for directly emitting a laser beam orthogonal to said top surface;
• an intermediate layer of silicon between said surface emitting semiconductor laser and said top surface of said semiconductor chip;
• an emission photodetector located on said top surface adjacent said surface emitting laser for monitoring a power output of said surface emitting laser;
• and
• a pair of four quadrant photodetectors for enabling the sensing of the shape of a reflected, diffracted beam of a beam emitted by said surface emitting laser from the difference in the amount of said reflected laser beam detected by each of said detectors, said pair of four quadrant photodetectors being located on opposite sides of said surface emitting laser, with each of said four quadrant photodetectors being at an angle of approximately 90 degrees to a line between said surface emitting laser and said emission photodetector.