Manufacturing method of semiconductor laser diode
Granted: November 23, 2004
Patent Number:
6821801
The invention provides a manufacturing method of a laser diode having buried grown layer with less crystal defects and with low consumption power and having high reliability in a buried heterostructure laser diode using an InGaAlAs type material as an active layer, by preventing the inhibition of burying and regrowing of the active layer caused by oxidation of Al contained in the active layer.
A manufacturing method of a semiconductor laser diode and the active layer comprises a…
Optical module with a monitor photo diode
Granted: November 2, 2004
Patent Number:
6813102
A PD (20) is mounted to a position offset (23) as viewed in the direction orthogonal to the center of an optical axis (14) of backward light (13) of an LD (11) in such a manner that a light receiving plane (21) thereof becomes substantially parallel to the center of the optical axis. Alternatively, the PD (20) is mounted thereto so that the light receiving plane of the PD is inclined at angles ranging from about 0° to about 30° to the center of the optical axis of the backward…
Optical communication module, manufacturing method thereof and wavelength selective filter
Granted: October 19, 2004
Patent Number:
6805496
The incident angle of the beam with regard to an etalon is arranged finely tunable by either rotating the etalon provided with a plane of incidence inclined with regard to the rotational axis thereof in the vicinity of the optical axis or rotating a lens whose edge surface is obliquely ground around the optical axis, which allows the incident angle of the laser beam with regard to the etalon to be adjusted and fixed with high precision.
Semiconductor photodetector device and manufacturing method thereof
Granted: October 5, 2004
Patent Number:
6800914
Reducing a dark current in a semiconductor photodetector provided with a second mesa including an regrown layer around a first mesa. An n-type buffer layer, a n-type multiplication layer, a p-type field control layer, a p-type absorption layer, a cap layer made of p-type InAlAs crystal, and a p-type contact layer 107 are made to grow on a main surface of a n-type substrate. Thereafter the p-type contact layer, the p-type cap layer, the p-type absorption layer and the p-type field control…
Panel mountable electronic device
Granted: April 27, 2004
Patent Number:
6728098
A panel mountable electronic device includes a housing having a flange through which passes a hole, a tab having a threaded hole, and a screw. In some embodiments, the electronic device is an optical transceiver and includes optical as well as electronic connections. The disclosed electronic device may be mounted to a panel by inserting the screw through the hole in the flange and into the threaded hole in the tab, inserting a portion of the housing through an opening in the panel, and…
Optical wavelength stabilization circuit, optical transmitter and optical transmission system
Granted: February 17, 2004
Patent Number:
6693932
In the initial state, any wavelength variation of the output signal light with a change of the current injected into the laser is monitored with a wavelength meter, the quantity of wavelength variation is fed back to the wavelength compensation circuit, a compensation voltage for maintaining the wavelength in the initial stage is figured out, and that voltage is recorded into a memory element or the like. A configuration to add this compensation voltage to a comparator makes it possible…
Semiconductor electro-absorption optical modulator integrated light emission element light emission element module and optical transmission system
Granted: January 13, 2004
Patent Number:
6678479
For achieving a transmission light source having different transmission properties or characteristics, i.e., the a parameters, depending upon application thereof, in a light emission element of semiconductor EA modulator integrated type being constructed with a light emission portion for lasing with a single vertical mode and a plurality of EA modulators, wherein an absorption edge wavelength under the condition of applying no bias thereto, in the semiconductor multiple-quantum-well…
Optical receiver circuit and optical module using same in optical communication system
Granted: July 22, 2003
Patent Number:
6595708
An optical receiver circuit comprising: a pre-amplifier for amplifying a signal supplied from a photodetector to output positive and negative signals; first and second peak hold circuits for detecting maximum levels of these positive and negative signals respectively; an offset canceler circuit for compensating the positive signal at the maximum level of the negative signal, for compensating the negative signal at the maximum level of the positive signal, and for then performing…
Optical transmission method and optical transmitter with temperature compensation function
Granted: May 6, 2003
Patent Number:
6559995
An optical transmitter comprises a modulator for generating a modulated current in accordance with a modulation control signal, a light emitting element driven by the modulated current from the modulator to emit light in accordance with the modulated current, a first current source for supplying the modulator with a driving current, a first temperature detector for detecting an operating temperature of the modulator to output a signal indicative of a detected operating temperature of the…
Optical receiver module optical transmitter module phase-locked loop circuit voltage-controlled oscillator and frequency response controllable amplifier
Granted: December 31, 2002
Patent Number:
6501583
Two sets of a high speed differential amplifier and a low speed differential amplifier are prepared, and frequency response speeds of these high speed/low speed differential amplifiers are different from each other. Both an oscillating frequency and a frequency modulation sensitivity of a ring oscillator type voltage-controlled oscillator circuit can be separately set by adding two outputs of these differential amplifiers to each other and by varying the selection ratio of these high…
