Abstract: A buried heterostructure window device has an elongated layer of gain medium surrounded by a lower index of refraction medium for guiding light along the length of the gain medium. A window and an antireflective layer are deposited on the output end of the gain layer to minimize reflections. A portion of the gain medium nearer the output end of the device is electrically pumped, leaving an unpumped end of the gain medium remote from the output end. The unpumped portion of the gain medium absorbs light travelling along the length of the gain medium. This inhibits reflection from the end of the gain medium remote from the output end. When the device is pumped with a moderate power level, strong superluminescent output is obtained. When the device is pumped well above the lasing threshold by reason of "burning through" the unpumped absorbing portion of the gain medium, a single mode laser is obtained with side band power at least 20 db below the power of the principal oscillation mode.

Abstract: A buried heterostructure window device has an elongated layer of gain medium surrounded by a lower index of refraction medium of guiding light along the length of the gain medium. A window and an antireflective layer are deposited on the output end of the gain layer to minimize reflections. A portion of the gain medium nearer the output end of the device is electrically pumped, leaving an unpumped end of the gain medium remote from the output end. The unpumped portion of the gain medium absorbs light travelling along the length of the gain medium. This inhibits reflection from the end of the gain medium remote from the output end. When the device is pumped with a moderate power level, strong superluminescent output is obtained. When the device is pumped well above the lasing threshold by reason of "burning through" the unpumped absorbing portion of the gain medium, a single mode laser is obtained with side band power at least 20 db below the power of the principal oscillation mode.

Abstract: A system and method are described for the real-time conversion of a two-cr optical input into coherent light of two colors. The system includes a first electrooptic device oriented to receive the optical input, the device having applied thereto a periodic voltage producing an electrical field periodically varying between magnitudes effective to block one or the other color of the optical input. The system further includes a second electrooptic device oriented to produce coherent light of two colors, this device having applied thereto a second periodic voltage in synchronization with the first-mentioned voltage to produce an electrical field periodically varying between magnitudes effective to block one or the other color of the coherent light source. A gate applies the second periodic voltage to the second electrooptic device only when light of either of the two colors is outputted by the first electrooptic device.