摘要:
A method for integrating a DFB laser and a passive strip waveguide on a substrate. A layer stack is produced in a first epitaxy step, the layer stack having a laser-active layer and a surface-wide grating on the uppermost layer, and eroding the stack area-wise, but only down to a layer under the laser-active layer, not down to the substrate, by means of etching to create a step separating the laser region from the passive strip waveguide region. By employing an etching stop layer, the etching can ensue self-adjustingly, and the coupling between the laser-active layer and the passive strip waveguide region occurs not by end coupling, but by surface coupling. Only two epitaxy steps are required for the complete manufacture of the structure, and a strip required for the definition of the laser and of the waveguide can be produced in the same single method step.
摘要:
A monolithically integrated WDM demultiplex module has a film wave guide of InGaAsP fashioned on a substrate, a photodiode of InGaAs being applied to the film wave guide. The photodiode is optically coupled to the film wave guide by a leakage coupling. A wavelength selection element in the form of a grating is provided in the surface of the film wave guide. The module can be manufactured with a single epitaxial step. Structures for increasing the crosstalk attenuation of the module and for a better coupling-in of radiation into the module are provided.
摘要:
Elements and methods for forming elements that operate with acoustic waves are disclosed. The element includes a piezoelectric electric substrate that has a first thermal coefficient of expansion, electrically conducting element structures on an upper side of the substrate, a compensation layer on an underside of the substrate, and an SiO2 layer over the element structures.
摘要:
An electrical module includes a base plate having an acoustic channel that opens into a first cavity at a first end and that is closed off by a microphone chip at a second end. The microphone chip borders a second cavity that opens to an exterior of the electrical module. The second cavity is separated from the acoustic channel by the microphone chip.
摘要:
The invention relates to a microphone membrane (M1) comprising two piezoelectric layers (PS1, PS2) with c-axes oriented in the same direction. A first electroconductive surface (E11) is formed in the central metal layer and subjected to a first electrical potential. The piezoelectric layers (PS1, PS2) are respectively arranged between the central metal layer (ML2) and an outer metal layer (ML1, ML3). In a preferred embodiment, the membrane (M1) has a largely symmetrical structure in terms of the layer sequence and the layer thickness thereof.
摘要:
A microphone includes a first diaphragm and a second diaphragm coupled to the first diaphragm by a closed air volume. The first diaphragm and the second diaphragm each constitutes a piezoelectric diaphragm. The first diaphragm and the second diaphragm are electrically coupled so that movement of the first diaphragm causes movement of the second diaphragm.
摘要:
An electrical module includes a base plate having an acoustic channel that opens into a first cavity at a first end and that is closed off by a microphone chip at a second end. The microphone chip borders a second cavity that opens to an exterior of the electrical module. The second cavity is separated from the acoustic channel by the microphone chip.
摘要:
An integrated optical arrangement operated as a switch composed of at least three ridge waveguides on a substrate, the third ridge waveguide is utilized for an infeed of an optical waveguide proceeding between two parallel ridge waveguides forming the first and second waveguides having either a contacted pn-junction or a contacted pin-junction. As a result of asymmetrical switching of the junctions, the optical wave is coupled over into one or the other of the first and second waveguides. The advantage over traditional directional coupler switch structures are complete symmetry of the two switch conditions, "digital switching behavior", enhanced separation of the output waveguide, low switching losses and greater manufacturing tolerances, reduced polarization sensitivity and increased optical bandwidth.
摘要:
A window function optimum for apodization of diffraction at an aperture of a Bragg Cell spectral analyzer. A window function is derived which is simpler to realize and which comes very close to an optimum window function.
摘要:
An apparatus including a piezoelectric substrate having at least one transducer electrode structure. The structure having a metallization formed by one or more metals with a mean specific density that is at least 50% higher than that of aluminum. The structure having a compensation layer that is applied fully or partially over the metallization. The compensation layer is of a material having a temperature dependence of elastic constants that counteracts the temperature coefficient of frequency of the substrate. The compensation layer has a thickness that is less than 15% of an acoustic wavelength of a wave capable of propagation in the structure.