Monolithic InP-Based Grating Spectrometer for Wavelength-Division Multiplexed Systems at 1.5 μm

A monolithic InP-based grating spectrometer for use in wavelength-division multiplexed systems at 1.5 μm is reported. The spectrometer uses a single etched reflective focusing diffraction grating and resolves >50 channels at 1 nm spacing with a ~0.3nm channel width and at least 19dB channel isolation. Operation is essentially of the state of the input polarisation

Fast high-efficiency integrated waveguide photodetectors using novel hybrid vertical/butt coupling geometry

We report a novel coupling geometry for integrated waveguide photodetectors−a hybrid vertical coupling/butt coupling scheme that allows the integration of fast, efficient, photodetectors with conventional double heterostructure waveguides. It can be employed to yield a planar, or pseudo-planar, surface that supports further levels of integration. The approach is demonstrated with a 25-µm-long p-i-n detector integrated with an InP/InGaAsP/InP waveguide, which displays a high (~90%) efficiency and large (~15 GHz) bandwidth. This is the fastest high-efficiency integrated waveguide photodetector reported to date

Spectrometer On A Chip: An InP-based Grating Demultiplexer For WDM Applications At 1.5μm

We report an InP-based grating spectrometer for WDM systems operating in the 1.5µm fiber band. The spectrometer resolves more than 50 wavelength demultiplexed channels at 1mm spacing with a 3Λ channel width and at least 19dB isolation between outputs. The spectrometer operation is almost independent of the state of the input polarization

Spectrometer on a chip: InP-based integrated grating spectrograph for wavelength-multiplexed optical processing

We report the performance of an InP-based integrated spectrometer and consider its application in wavelength division multiplexed (WDM) systems. The wavelength multiplexer/demultiplexer operates in the 1.5 micrometers fiber band and disperses 1 nm spaced signals over a spectral range of 75 nm. Crosstalk between the channels is -19 dB and the optical performance of the spectrometer is essentially insensitive to the polarization of the incident light. Use of the device in multiwavelength telecommunication and computer local area networks is discussed

Ultracompact monolithic integration of balanced, polarization diversity photodetectors for coherent lightwave receivers

The authors have monolithically integrated an optical front-end on InP for balanced, polarization-diversity coherent lightwave reception which is only 1.3-mm long. Low on-chip insertion loss (<4.5 dB) and balanced photoresponse (1.05:1 or better) are achieved at 1.5-μm wavelength using straightforward, regrowth-free fabrication. Low-capacitance photodetectors (≤0.15 pF) are employed for high bandwidth operation

WDM Detection Using Integrated Grating Demultiplexer And High Density p-i-n Array

Multi-wavelength systems are being advocated for use in future telecommunication networks and for computer processor links. In research systems the multiplexing and demultiplexing of the different wavelength signals is currently achieved through the use of bulk optical components. When channel separation are on the order of a nm or so - which is typical of 'high density' direct detection systems - the MUX/DMUX function is generally done with a diffraction grating. WDM detection at the receiver end is then obtained by assembling a detector array, placed in the focal plane of the optical grating system

BioMEMS to bionanotechnology: state of the art in integrated biochips and future prospects

Biomedical or Biological Micro-Electro-Mechanical- Systems (BioMEMS) have in recent years become increasingly prevalent and have found widespread use in a wide variety of applications such as diagnostics, therapeutics and tissue engineering. This paper reviews the interdisciplinary work performed in our group in recent years to develop micro-integrated devices to characterize biological entities. We present the use of electrical and mechanically based phenomena to perform characterization and various functions needed for integrated biochips. One sub-system takes advantage of the dielectrophoretic effect to sort and concentrate bacterial cells and viruses within a micro-fluidic biochip. Another sub-system measures impedance changes produced by the metabolic activity of bacterial cells to determine their viability. A third sub-system is used to detect the mass of viruses as they bind to micro-mechanical sensors. The last sub-system described has been used to detect the charge on DNA molecules as it translocates through nanopore channels. These devices with an electronic or mechanical signal output can be very useful in producing practical systems for rapid detection and characterization of cells for a wide variety of applications in the food safety and health diagnostics industries. The paper will also briefly discuss future prospects of BioMEMS and its possible impact and on bionanotechnology

Low-loss, Ultra-compact Monolithic Integration Of High-speed Polarization-diversity Photodetectors

Polarization-selective optical devices are required for polarization-diversity coherent lightwave receivers.[l] Monolithic integration of such devices with photodetectors improves detector functionality and eliminates package complexity by reducing part count and hybrid optical interconnects. Compatibility with high III-V materials' cost, however, requires simple, high-yield processes and compact device size. We previously proposed a simple and compact integration scheme employing metal-loaded vertical couplers for polarization splitting and vertically-coupled photodiodes for O/E conversion. Initial experiments using InGaAsP/InP demonstrated satisfactory optical functionality, with 10.6 and 16dB polarization selectivity for TE and TM polarized-light.[2] Here we show how such integrated devices can be modified to achieve suitable electronic performance, including wide bandwidth and high quantum efficiency

Monolithic WDM Sources And Detectors For The Long Wavelength Fiber Band Based On An InP Grating Multiplexer/demultiplexer

Wavelength Division Multiplexed (WDM) networks are currently attracting considerable attention worldwide. Applications envisaged are wide-ranging - from computer back-plane interconnects and the telephone local loop, through local- and metropolitan- area networks, to wide-area networks involving advanced wavelength routing schemes [1, 2]

WDM Detection Using Integrated Grating Demultiplexer And High Density p-i-n Array

Multi-wavelength systems are being advocated for use in future telecommunication networks and for computer processor links. In research systems the multiplexing and demultiplexing of the different wavelength signals is currently achieved through the use of bulk optical components. When channel separation are on the order of a nm or so - which is typical of 'high density' direct detection systems - the MUX/DMUX function is generally done with a diffraction grating. WDM detection at the receiver end is then obtained by assembling a detector array, placed in the focal plane of the optical grating system