摘要:
An arrangement for providing optical crossovers between waveguides formed in an SOI-based structure utilize a patterned geometry in the SOI structure that is selected to reduce the effects of crosstalk in the area where the signals overlap. Preferably, the optical signals are fixed to propagate along orthogonal directions (or are of different wavelengths) to minimize the effects of crosstalk. The geometry of the SOI structure is patterned to include predetermined tapers and/or reflecting surfaces to direct/shape the propagating optical signals. The patterned waveguide regions within the optical crossover region may be formed to include overlying polysilicon segments to further shape the propagating beams and improve the coupling efficiency of the crossover arrangement.
摘要:
A practical realization for achieving and maintaining high-efficiency transfer of light from input and output free-space optics to a high-index waveguide of sub-micron thickness is described. The required optical elements and methods of fabricating, aligning, and assembling these elements are discussed. Maintaining high coupling efficiency reliably over realistic ranges of device operating parameters is discussed in the context of the preferred embodiments.
摘要:
An optical coupling system for use with multiple wavelength optical signals provides improved coupling efficiency between a free-space optical beam and a relatively thin, surface layer of an SOI structure (“SOI layer”), allowing for sufficient coupling efficiency (greater than 50%) over a predetermined wavelength range. An evanescent coupling layer, disposed between a coupling prism and an SOI layer, is particularly configured to improve the coupling efficiency. In one embodiment, the thickness of the evanescent layer is reduced below an optimum value for a single wavelength, the reduced thickness improving coupling efficiency over a predetermined wavelength range around a defined center wavelength. Alternatively, a tapered thickness evanescent coupling layer may be used to improve coupling efficiency (or a combination of reduced thickness and tapered configuration). Optical beam steering can be combined with a modified evanescent coupling layer to control the input beam launch angle and further improve coupling efficiency.
摘要:
A silicon-based IR photodetector is formed within a silicon-on-insulator (SOI) structure by placing a metallic strip (preferably, a silicide) over a portion of an optical waveguide formed within a planar silicon surface layer (i.e., “planar SOI layer”) of the SOI structure, the planar SOI layer comprising a thickness of less than one micron. Room temperature operation of the photodetector is accomplished as a result of the relatively low dark current associated with the SOI-based structure and the ability to use a relatively small surface area silicide strip to collect the photocurrent. The planar SOI layer may be doped, and the geometry of the silicide strip may be modified, as desired, to achieve improved results over prior art silicon-based photodetectors.
摘要:
A silicon-based optical modulator structure includes one or more separate localized heating elements for changing the refractive index of an associated portion of the structure and thereby providing corrective adjustments to address unwanted variations in device performance. Heating is provided by thermo-optic devices such as, for example, silicon-based resistors, silicide resistors, forward-biased PN junctions, and the like, where any of these structures may easily be incorporated with a silicon-based optical modulator. The application of a DC voltage to any of these structures will generate heat, which then transfers into the waveguiding area. The increase in local temperature of the waveguiding area will, in turn, increase the refractive index of the waveguiding in the area. Control of the applied DC voltage results in controlling the refractive index.
摘要:
A vertical stack of integrated circuits includes at least one CMOS electronic integrated circuit (IC), an SOI-based opto-electronic integrated circuit structure, and an optical input/output coupling element. A plurality of metalized vias may be formed through the thickness of the stack so that electrical connections can be made between each integrated circuit. Various types of optical input/output coupling can be used, such as prism coupling, gratings, inverse tapers, and the like. By separating the optical and electrical functions onto separate ICs, the functionalities of each may be modified without requiring a re-design of the remaining system. By virtue of using SOI-based opto-electronics with the CMOS electronic ICs, a portion of the SOI structure may be exposed to provide access to the waveguiding SOI layer for optical coupling purposes.
摘要:
An improvement in the reliability and lifetime of SOI-based opto-electronic systems is provided through the use of a monolithic opto-electronic feedback arrangement that monitors one or more optical signals within the opto-electronic system and provides an electrical feedback signal to adjust the operation parameters of selected optical devices. For example, input signal coupling orientation may be controlled. Alternatively, the operation of an optical modulator, switch, filter, or attenuator may be under closed-loop feedback control by virtue of the inventive monolithic feedback arrangement. The feedback arrangement may also include a calibration/look-up table, coupled to the control electronics, to provide the baseline signals used to analyze the system's performance.
摘要:
An improvement in the reliability and lifetime of SOI-based opto-electronic systems is provided through the use of a monolithic opto-electronic feedback arrangement that monitors one or more optical signals within the opto-electronic system and provides an electrical feedback signal to adjust the operation parameters of selected optical devices. For example, input signal coupling orientation may be controlled. Alternatively, the operation of an optical modulator, switch, filter, or attenuator may be under closed-loop feedback control by virtue of the inventive monolithic feedback arrangement. The feedback arrangement may also include a calibration/look-up table, coupled to the control electronics, to provide the baseline signals used to analyze the system's performance.
摘要:
An opto-electronic apparatus comprises a substrate for supporting a plurality of components forming an opto-electronic assembly and an optical component attached to the substrate with an adhesive material, such as a solder or epoxy. The optical component is formed to include a plurality of bond slots disposed in parallel across at least a portion of the bottom surface of the optical component, the plurality of bond slots providing a path for a liquid adhesive material and improving the ability to displace the liquid adhesive material as the component is pressed into the surface of the substrate during the attachment process.
摘要:
A silicon-insulator-silicon capacitive (SISCAP) optical modulator is configured to provide analog operation for applications which previously required the use of relatively large, power-consuming and expensive lithium niobate devices. An MZI-based SISCAP modulator (preferably a balanced arrangement with a SISCAP device on each arm) is responsive to an incoming high frequency electrical signal and is biased in a region where the capacitance of the device is essentially constant and the transform function of the MZI is linear.