摘要:
A laser resonator (11) and a passive resonator (7,22) are coupled longitudinally in such a way as to prevent multiple reflections in the laser (11). The passive resonator (7,22) is, for example, monolithically integrated in laser (11). In a semiconductor wafer (5), a laser-active layer (1) and a waveguide layer (2) transparent to the laser beam are arranged at such a distance apart that no optical coupling occurs through the intermediate semiconductor material. The semiconductor wafer (5) has a cavity (7) perpendicular to the direction of layering and perpendicular to the propagation of the light, with a vertical flank (71) which forms a common reflecting surface of the laser (11) and the passive resonator (7,22) and an inclined flank (72) which reflects the light not coupled to the waveguide layer (22) forming part of the resonator out of the wafer (5).
摘要:
A laser diode array includes ridges formed in a cover layer forming an upper layer of a semiconductor body, the ridges being provided with separate contacts to produce laser active stripes in an active layer situated between a substrate and the cover layer. The thickness of the cover layer between the ridges is such that lateral coupling is achieved, while the thickness of the cover layer in the region adjoining the outside edges of the outer ridges is small enough so that lateral emission losses are low as the result of quasi-index guidance based on the metal clad ridge waveguide principle. A second embodiment provides wave guidance at the outside edges of the outer ridges by a buried heterostructure principle.
摘要:
An apparatus for ventilating high speed elevator cars during the travel with closed doors includes upper and lower ventilation systems having primary air openings formed in troughs located in the upper and lower portions of the car body. The pressure of the incoming air is relieved and the air is smoothed in steps in air chambers and air channels such that the air flows free of drafts and noiselessly into the interior of the car. The ventilation of the elevator car takes place through the ventilation apparatus in the direction of travel of the car, since both the ventilation systems provide flow through in both directions of travel of the car.
摘要:
A semiconductor diode laser for tunable single-frequency laser radiation has a plurality of laser-active strips associated with a semiconductor body having first and second reflective end surfaces. The first end surface has laser radiation emitted and coupled out therefrom. One of the strips is an emitting laser-active strip which emits the laser radiation and the further laser-active strips are provided at both sides of the emitting strip. The further strips are shorter than the emitting strip and are provided such that respective resonators corresponding to each strip are provided with mirrors or reflectors at both ends thereof. A first end of the strips terminates in front of the first end face of the semiconductor body.
摘要:
A circuit arrangement for generating light pulses includes an electro-optical converter; a switching element; and a charge store. The electro-optical converter is connected to the charge store via the switching element. The closing of the switching element triggers a discharging process in the charge store and, in the process, generates an electrical pulse that is converted to a light pulse in the electro-optical converter. First and second impedance matching circuits are arranged, respectively, between the charge store and the switching element and between the switching element and the electro-optical converter.
摘要:
The invention relates to a device (1) for writing on thermographic material (5). The inventive device (1) comprises a heater (20) with which the thermographic material (5) is preheated to a temperature, which is lower than a writing temperature. The thermographic material (5) can be written on with a writing instrument (10) which is distanced from the thermographic material (5) after input of an information signal (s(t)). The writing instrument (10) has a plurality of individually controllable point sources (30-33; 51-53). The thermographic material (5) can be written on in a point-by-point manner with said point sources (30-33; 51-53).
摘要:
The invention concerns a method of operating a laser diode (2) producing a beam (9) whose intensity is controlled by a control signal and which is directed along a first beam path (10) at the target surface (5), stray reflections from the target surface (50 which are unstable with respect to the diode (2) in time and/or space acting on the diode (2). An element (19, 28, 31, 37, 38) which is stable in time and with respect to the diode (2) in space is used to feed part of the light emitted by the diode back along a second beam path (11) to the active zone (42) of the diode (2) so that the diode (2) is kept in a state of coherence collapse.
摘要:
A method for adjusting the intensity of a laser beam which is generated by a laser diode which is controlled by an adjustment signal and a noise signal. A circuit for intensity adjustment for the modulation of a laser beam generated by a laser diode which includes a control means of an adjustment signal, means for generating a noise signal, and means for controlling the laser diode with the noise signal and the adjustment signal.
摘要:
A laser transmitter arrangement includes a plurality of laterally coupled semiconductor lasers along with drive components integrated on a single semiconductor body. The drive components include drop resistors, an inductance element, a capacitance element and are all applied to an insulating layer on the surface of the semiconductor body. The resistors are formed by interconnects, while the inductance element is a spiral interconnect and the capacitance element is formed by interconnects lying over one another with an intervening dielectric material. Electrical connection from contact surfaces of the semiconductor lasers to the drive components is provided by the interconnects. The semiconductor body also contains external contacting surfaces for a DC source and for a high frequency source.
摘要:
The invention provides a device and method for wireless transmission of energy. An electromagnetic field used for transmitting energy is generated using a resonator system comprising a plurality of weakly coupled resonators, the resonator system having a plurality of eigenmodes with different eigenfrequencies. At least one generator is coupled to one of the resonators. The resonator is configured to operate the resonator system at one of the plurality of eigenmodes, thereby generating a spatially coherent magnetic field adapted for transmitting energy to an appliance.