Integrated laser-based light source

• Main Authors: WANG, SHIH-YUAN, BALDWIN, RICHARD R, TAN, MICHAEL R.T, ERTEL, JOHN P, ZHANG, TAO, LARSON, LEIF ERIC, CORZINE, SCOTT W, YUEN, ALBERT Y, SEARS, DAVID M, HOLLAND, WILLIAM D
• Format: Patent
• Language: English; French; German
• Published: 29.03.2000
• Edition: 7
• Subjects: BASIC ELECTRIC ELEMENTS; DEVICES USING STIMULATED EMISSION; ELECTRICITY

An integrated laser-based light source (100,100A-100C,200,250,300,320,340,350,500,600,620,700,720,800,900), which generates an output light beam (119,819) having a controlled intensity, comprises a package (105) in which are mounted a laser (101, 801), a light sensor (111, 811) and a coupler (114, 314A-314D, 514, 614, 714, 814, 914). The laser has one and only one light-emitting face (e.g., 109) from which a light beam is radiated as a radiated light beam (107). The light sensor generates an electrical signal representing the intensity of light energy falling it. The coupler couples a fraction (117, 717, 917) of the radiated light beam to the light sensor, and provides the remainder of the radiated light beam as the output light beam. Since the light coupled to the light sensor by the coupler is a fraction of the radiated light beam, the electrical signal generated by the light sensor also represents the intensities of the radiated light beam and of the output light beam. A suitable control circuit (127, 827), when fed with the electrical signal generated by the light sensor, can control the laser current to hold the electrical signal generated by the light sensor to a predetermined value that corresponds to the output light beam having a predetermined intensity.