BOOKHAM TECHNOLOGY, PLC Patent applications |
Patent application number | Title | Published |
20110020013 | DEMODULATION OF AN OPTICAL CARRIER - A method of transmitting a plurality n data streams comprises modulating an optical carrier using differential M-ary phase shift key (DMPSK) signaling in which M=2 | 01-27-2011 |
20100220762 | HIGH POWER SEMICONDUCTOR OPTO-ELECTRONIC DEVICE - Semiconductor laser diodes, particularly broad area single emitter (BASE) laser diodes of high light output power, are commonly used in opto-electronics. Light output power and stability of such laser diodes are of crucial interest and any degradation during normal use is a significant disadvantage. The present invention concerns an improved design of such laser diodes, the improvement in particular significantly minimizing or avoiding degradation of such laser diodes at very high light output powers by controlling the current flow in the laser diode in a defined way. The minimization or avoidance of (front) end section degradation of such laser diodes significantly increases long-term stability compared to prior art designs. This is achieved by controlling the carrier injection into the laser diode in the vicinity of its facets in such a way that abrupt injection current peaks are avoided. To this, a current-blocking isolation layer ( | 09-02-2010 |
20100189152 | HIGH POWER SEMICONDUCTOR LASER DIODE - Semiconductor laser diodes, particularly broad area single emitter (BASE) laser diodes of high light output powers are commonly used in opto-electronics. Light output power and stability of such laser diodes are of crucial interest and any degradation during normal use is a significant disadvantage. The present invention concerns an improved design of such laser diodes, the improvement in particular significantly minimizing or avoiding (front) end section degradation at very high light output powers by controlling the current flow in the laser diode in a defined way. This is achieved by controlling the carrier injection, i.e. the injection current, into the laser diode in a novel way by creating single current injection points along the laser diode's longitudinal extension, e.g. along the waveguide. Further, the supply current/voltage of each single or group of current injection point(s) may be separately regulated, further enhancing controllability of the carrier injection. | 07-29-2010 |
20090245814 | OPTICAL COMMUNICATIONS - A method of transmitting a plurality n data streams comprises modulating an optical carrier using differential M-ary phase shift key (DMPSK) signalling in which M=2 | 10-01-2009 |
20090180501 | LASER TUNING - A method of controlling a laser is provided for generating an optical output. The method includes the step of making a change to an electrical input to the laser so as to move the optical output of the laser towards a target frequency, and also includes the step of changing the temperature of the laser in relation to the change in the electrical input or the movement of the optical output. The method further includes the step of making further changes to the electrical input as the temperature of the laser is changed so as to maintain the optical output of the laser at the target frequency. | 07-16-2009 |
20090141757 | OPTICAL AMPLIFIERS - An optical amplifier comprises an optical fibre, a pump laser for optically pumping the optical fibre to amplify an optical signal, a TEC | 06-04-2009 |
20090104727 | HIGH POWER SEMICONDUCTOR LASER DIODES - A high power laser source comprises a bar of laser diodes, a submount onto which said laser bar is affixed, and a cooler onto which said submount is affixed. The laser bar has a first coefficient of thermal expansion (CTE | 04-23-2009 |
20080240175 | Bragg Grating Reflection Strength Control - A tunable laser comprises a gain section and two or more reflectors. At least one of the reflectors is a Bragg grating comprising a reduced strength section comprising a base order periodic pattern of marks and spaces from at which at least some of the marks or spaces are missing. This enables the reflective strength of the grating to be controlled relative to the other reflector. The Bragg grating may be a phase change grating with individual sections being reduced in strength by line removal. | 10-02-2008 |
20080212167 | CASCADED OPTICAL AMPLIFIER AND CONTROL METHOD THEREOF - A cascaded optical amplifier including a first optical amplifier and a second optical amplifier in cascaded arrangement is provided. Each of the first optical amplifier and the second optical amplifier has a respective input for receiving an optical signal, an output for outputting an amplified optical signal, and a control input for controlling the gain of the optical amplifier. The cascaded optical amplifier includes a sensor for sensing upstream of the input of the second optical amplier a signal relating to operation of the cascaded optical amplifier. In addition, the cascaded optical amplifier includes a controller for providing control signals to the respective control inputs of the first amplifier and the second amplifier, the controller providing the control signal to the second optical amplifier as a function of the sensed signal. | 09-04-2008 |