Multiplexers Research Papers - Academia.edu (original) (raw)

The test of the Conjigurable Logic Blocks of RAM based FPGAs under a Stuck-At fault model has been studied. The high cost of changing the configuration, by reprogramming the FPGA during testing, forces a strategy to reduce the number of different configurations used for testing purposes. After finding the optimal solutions for the elementary structures of the Logic block, Multiplexers and Look-Up Tables, the problem of testing interconnected elementary structures is addressed The method is illustrated using an elementary structure and then applied to a popular FPGA (XILINX 3000 family) where a reduced set of configurations (5) and their corresponding test sequences is found to cover all (100%) the Configurable Logic Block faults modelled.

- by
- •
- Manufacturing, Reprogramming, FPGA, Field-Programmable Gate Arrays
- by Aneesh Koorapaty
- •
- Management, Computer Science, Algorithms, Design

Wideband Ti : LiNbO 3 optical modulators for 40 Gb/s applications, Proc. ECOC'98, Madrid, Spain, 1998, pp. 547-548. 24. S. Yamada and M. Minakata, DC drift Phenomenon in LiNbO 3 optical waveguide devices, Jpn. J. Appl. Phys. 20: 733-737 (1981). 25. M. Seino, T. Nakazawa, M. Doi, and S. Taniguchi, The long term reliability estimation of Ti : LiNbO 3 modulator for DC drift, Proc. IOOC'95, Hong Kong, paper PD1-8, 1995, pp. 15-16. 26. I. Sawaki, H. Nakajima, M. Seino, and K. Asama, Thermally stabilized z-cut Ti : LiNbO 3 waveguide switch, Proc.

- by Alexandros Stavdas
- •
- Wdm, Diffraction Gratings, Optical Filters, Multiplexers

Polymer Optical Fibres (POFs) show clear advantages compared to copper and glass fibres. In essence, POFs are inexpensive, space-saving and not susceptible to electromagnetic interference. Thus, the usage of POFs have become a reasonable alternative in short distance data communication. Today, POFs are applied in a wide number of applications due to these specific advantages. These applications include automotive communication systems and in-house-networks. State-of-the-art is to transmit data with only one channel over POF, this limits the bandwidth. To solve this problem, an integrated MUX/DEMUX-element for WDM over POF is designed and developed to use multiple channels. This integration leads to low costs, therefore this component is suitable for mass market applications. The fundamental idea is to separate the chromatic parts of the light in its monochromatic components by means of a grating based on an aspheric mirror. Due to the high NA of the POF the setup has to be designed in a 3D-approach. Therefore this setup cannot be compared with the planar solutions available on market, they would result high losses in the 3 rd dimension. To achieve a fast and optimized design an optical simulation program is used. Particular attention has to be paid to the design of the POF as a light source in the simulation program and the optimisation of the grating. The following realization of the demultiplexer is planed to be done with injection molding. This technology offers easy and very economical processing. These advantages make this technology first choice for optical components in the low-cost array.

- by Antonio d'Alessandro
- •
- Liquid Crystals, Optical Communication, Optical Switch, Optical switching

Mercury cadmium telluride is a promising detector material for low background astronomical imaging and spectroscopy in the near infrared. We have begun a program to measure dark current as a function of temperature in both isolated HgCdTe diode arrays and arrays which have been bump-bonded to silicon multiplexers. In this paper, we describe measurements of 2.5 μm cutoff diode material and a hybrid array with a CCD readout. Measurements of 52 μm x 52 μm detectors indicate that id may be less than 50-100 e-/sec at 87 K.

- by Mark Hereld
- •
- Engineering, Physics, Infrared Astronomy, Spectroscopy

The algebraic soft-decoding (ASD) of Reed– Solomon (RS) codes provides significant coding gain over hard-decision decoding with polynomial complexity. The low-complexity chase (LCC) algorithm is proposed for reducing the complexity of interpolation, which interpolates over 2^n test vectors, being attractive for VLSI implementation. The interpolation is simplified in LCC decoding by restricting the multiplicity to m=1 and replacing the factorization step with Chien’s search and Forney’s algorithm. In this paper, high-throughput interpolator architecture for soft-decision decoding of Reed– Solomon (RS) codes based on low-complexity chase (LCC) decoding is presented. We have formulated a modified form of the Nielson’s interpolation algorithm, using some typical features of LCC decoding. The proposed algorithm works with a different scheduling, takes care of the limited growth of the polynomials, and shares the common interpolation points, for reducing the latency of interpolation. Base...

- by Susrutha Babu Sukhavasi
- •
- Mathematics, Registers, Multiplexers, D Flip Flop

The HAWAII-2 is an infrared 2048 2 focal plane array (FPA) that is being developed for next-generation infrared astronomy. It will supplant our HAWAII 1024 2 as the largest high-performance imaging array available for IR astronomy. As with our prior infrared sensors, the flip-chip hybrid will consist of a low-capacitance HgCdTe detector array mated to a low-noise CMOS silicon multiplexer via indium interconnects. In order to accommodate reasonable telescope optics and fabrication of the large sophisticated readout (40 x 40 mm 2) using world-class submicron CMOS, the FPA has 18 µm pixel pitch. We anticipate >5% yield of defect-free multiplexers using 0.8 µm CMOS. The HgCdTe detector arrays will be fabricated on large wafers including sapphire and silicon. Though the first FPAs will have 2.5 µm cutoff , the readout will be able to support longer wavelengths. Also reported are the latest 1024x1024 FPA results with 2.5 µm HgCdTe detectors.

- by Lester Kozlowski
- •
- Optics, Infrared Astronomy, Sensors, Fabrication

- by Lester J Kozlowski
- •
- Optics, Infrared Astronomy, Sensors, Fabrication

This paper presents two proposed circuits that employ a footer transistor that is initially OFF in the evaluation phase to reduce leakage and then turned ON to complete the evaluation. Also a new circuit is added using a NAND gate that improves the performance more than 10% -15% compared with latter proposed circuit. According to simulations in a predictive 70 nm process, the proposed circuit increases noise immunity by more than 26X for wide OR gates and shows performance improvement of up to 20% compared to conventional domino logic circuits. The proposed circuit reduces the contention between keeper transistor and NMOS evaluation transistors at the beginning of evaluation phase. High fan-in comparators and multiplexers demonstrate high noise immunity compared with previous proposed works.

- by Farshad Moradi
- •
- Multiplexer, Predictive models, Crosstalk, Logic Gates

Distributed Arithmetic (DA) has been successfully applied to the design of area efficient multipliers on FPGAs for DSP applications. Whilst DA is efficient in applications where coefficients are fixed, there is little option for applications with a limited range of coefficient values. This paper describes a technique for developing areaefficient multipliers for a range of DSP applications that fall into this category. This is accomplished by employing multiplexers at no extra cost to increase the functionality of existing fixed coefficient multipliers. The technique has been applied to a DCT FPGA implementation where an area decrease of up to 50% and speed increase of 33% was achieved over the conventional route.

This paper analyzes the advantages and limitations of using the floating-(or flying-) capacitor technique as fully differential or differential input but single-ended output building block to implement voltage amplifiers, multiplexers and coherent amplitude demodulators. Theoretical analysis supported by experimental results show that the fully differential configuration has a better common mode rejection ratio (CMRR). However, if the signal, once amplified, must be single ended, then in amplifiers and some multiplexers it may be better to have a floating capacitor with single-ended output whilst in demodulators a floating capacitor with differential output yields a better CMRR.

- by Josep M Torrents
- •
- Sampling methods, Data acquisition, Multiplexing, Impedance

In this paper we propose an efficient scheme for implementing a complex multiplier based on distributed arithmetic. A modified bit-serial shift-accumulator for distributed arithmetic is also proposed for computing a * b+c, where a, b, and c are complex numbers. The shift-accumulator is highly regular and modular and consists of only three types of bit-slices, each of which consists of only three types of blocks, multiplexers, exclusive OR gates, and latches. The implementation is done using a robust differential single-phase clocked logic style suitable for high-speed and low power operation. The resulting implementation of the complex multiplier has a maximum clock frequency of 250 MHz, consumes 70 mW, and occupies a chip area of 0.5 mm 2 in a double-metal 0.8 µm process. The coefficient word length and the data word length are 12 bits and 16 bits, respectively.

- by Lars Wanhammar
- •
- Distributed Computing, Logic, Differential Equations, Arithmetic

In the age of information society and internet the requirements of fast transfers of large data streams for different applications are growing day by day. Killer-applications like teleconferencing, video-on-demand, online-games, virtual reality etc. are waiting in the wings. The optical network technology using the great bandwidth of glass fibre is the most suitable technology for these demands. Not only glass fibre is required, but also a broad range of optical components, such as multiplexers, demultiplexers, optical switches, optical attenuators, splitters and combiners, which are usually produced in silica technology. Polymeric materials are becoming more and more interesting for these applications, since they promise for instance lower power consumption and a reduction of production costs compared to their silica based pendants. Polycyanurate ester resins are a relatively new class of high-performance polymers with outstanding properties, for example high thermal stability, low optical loss, low dielectric constant, good adhesion and outstanding mechanical properties. This paper focuses on optical loss and birefringence of such materials at 1550 nm. The results lead the way to optimization for use in integrated optics and for the production of embedded waveguides and devices.

- by Joerg Bauer
- •
- Information Society, Video, Optical Switch, Optical switching

A novel design of Multiplexer-Demultiplexer (MUX-DEMUX) based on index guiding soft glass nematic liquid crystal (NLC) based photonic crystal fiber coupler is proposed and analyzed. The simulation results are obtained using the full vectorial finite difference method as well as the full vectorial finite difference beam propagation method. The numerical results reveal that the proposed MUX-DEMUX of length 3.265 mm can provide low crosstalk better than −20 dB with great bandwidths of 40 and 24 nm around the wavelengths of 1.3 and 1.55 µm, respectively. In addition, the reported MUX-DEMUX has a tolerance of ±3% in its length which makes the design more robust to the perturbation introduced during the fabrication process.

- by Salah Obayya
- •
- Liquid Crystals, Glass, Optical Waveguides, Optical physics

Photonic circuits based on silicon wire waveguides have attracted significant interest in recent years. They allow strong confinement of light with moderately low propagation losses. Moreover, the high thermo-optical coefficient of silicon and the small device size in silicon photonics allow for micro-heaters induced trimming, tuning, and switching with relatively low power. In this paper, we review our recent progress towards telecom-grade reconfigurable optical adddrop multiplexers (ROADMs) based on silicon microring resonators. We discuss waveguide and micro-heater design and fabrication as well as the first demonstration of telecom-grade silicon-microring filters and the first demonstration of transparent wavelength switching. The reported devices can be employed in numerous optical interconnect schemes.

- by Milos Popovic
- •
- Photonic Integrated Circuits, Telecommunications, Resonators, Silicon Photonics

There is an increasing demand for DWDM systems to support a set of network requirements (span length, total distance, capacity, etc) typically associated with previously distinct network application categories such as access, metro, regional, and long haul. This has led to the development of a multi-haul DWDM system, defined as an agile optical platform, able to combine multiple versions of transponders, amplifiers, and optical add/drop multiplexers (OADM) on the same optical link. The concept of a multi-haul system is applied in a study of DWDM networks that can employ, besides fixed OADM, two types of reconfigurable OADM (ROADM): a two-degree ROADM based on arrayed-waveguide gratings (AWG) and a multi-degree ROADM built with 5x1 wavelength-selective switches (WSS). A cost analysis on a network example calculates the savings obtained if an optimum mix of ROADMs is used on the same DWDM ring instead of deploying one single OADM type at all nodes. A technical feasibility study is performed to validate the performance of a DWDM system with up to 16 ROADMs in a network. To this purpose, OSNR penalties are experimentally determined for AWG and WSS ROADMs due to cascaded bandwidth narrowing, and crosstalk effects, with wavelength detuning values corresponding to locked and unlocked lasers.

- by Dogan Atlas
- •
- Engineering, Physics, Optimization, Feasibility Study

We demonstrate a silica-based tunable fiber Bragg grating (TFBG) filter with a wavelength tuning range over 60 nm. A magnetically TFBG package is employed to obtain a wide wavelength tuning range from 1540 to 1602 nm which covers the... more

- by Heba Fayed
- •
- Photonics, Optical Communication, Dispersion, Fiber Bragg grating

We have designed a detector package to house a superconducting bolometer array, SQUID multiplexers, bias and integration circuitry, optical filtering, electrical connectors, and thermal/mechanical interfaces. This package has been used successfully in the GISMO 2mm camera, a 128-pixel camera operating at a base temperature of 270mK. Operation at lower temperatures is allowed by providing direct heat sinking to the SQUIDs and bias resistors, which generate the bulk of the dissipation in the package. Standard electrical connectors provide reliable contact while enabling quick installation and removal of the package. Careful design has gone into the compensation for differing thermal expansions, the need for heat sinking of the bolometer array, and the placement of magnetic shielding in critical areas. In this presentation, we detail the design and performance of this detector package and describe its scalability to 1280-pixel arrays in the near future.

- by Johannes Staguhn
- •
- Engineering, Physics, Performance, Astronomy

The increasing demand of new services and applications is pushing for drastic changes on the design of access networks targeted mainly for residential and SOHO users. Future access networks will provide full service integration (including multimedia), resource sharing at the packet level and QoS support. It is expected that using IP as the base technology, the ideal plug-and-play scenario, where the management actions of the access network operator are kept to a minimum, will be achieved easily. This paper proposes an architecture for access networks based on layer 2 or layer 3 multiplexers that allows a number of simplifications in the network elements and protocols (e.g. in the routing and addressing functions). We discuss two possible steps in the evolution of access networks towards a more efficient support of IP based services. The first one still provides no QoS support and was designed with the goal of reusing as much as possible current technologies; it is based on tunneling to transport PPP sessions. The second one introduces QoS support through the use of emerging technologies and protocols. We illustrate the different phases of a multimedia Internet access session, when using SIP for session initiation, COPS for the management of QoS policies including the AAA functions and RSVP for resource reservation.

- by Henrique Sousa
- •
- Engineering, Computer Science, Multimedia, Resource Allocation

The increased flexibility offered by FPGAs implies that more transistors are needed which leads to higher power consumption per logic gate. FPGAs power consumption is fast becoming an essential design consideration especially for mobile systems with a limited power supply. The effect of components' region-constrained placement on reducing internal nets total capacitance and the corresponding change in internal nets' total dynamic power consumption is investigated. Two logic circuits were specified as components covering around 80% of total FPGA busy gates. These components are multiplexers and adders along with multipliers. Each of these components was implemented on two of Xilinx FPGA's families, namely; Spartan II and Virtex. Gatelevel power estimation for different region-constrained placements of each logic circuit was carried out using the Xilinx hierarchal power distribution analyzer, XPower.

Recently ESO has commissioned the HAWK-I camera which is equipped with a 2x2 mosaic of λ c~ 2.5 μm HAWAII-2RG arrays. The arrays have high quantum efficiency and achieve photon shot noise limited performance on the telescope. Using reference pixels it can be shown that the readout noise for most arrays is limited by the MBE grown HgCdTe material and not by the multiplexer or the data acquisition chain. Results obtained with the guide window of the HAWAII-2RG multiplexer will be presented. Inter-channel crosstalk and fringing in the detector substrate will be discussed. The dynamic range of detectors can be expanded by applying threshold limited integration (TLI) to the follow-up-the-ramp nondestructive sampling scheme. For substrate removed arrays a calibration technique based on the X-ray emission of Fe 55 will be discussed.

- by Gert Finger
- •
- Performance, Molecular beam epitaxy, Astronomy, Sensors
- by Aditya Wardana
- •
- Multiplexers

This paper presents a new and efficient method for concurrent BIST synthesis and test scheduling. The method maximizes concurrent testing of modules while performing the allocation of functional units, test registers, and multiplexers. The method is based on a genetic algorithm that efficiently explores the testable design space. The method was implemented using C++ on a Linux workstation. Several benchmark examples have been implemented and favorable results are reported.

- by Haidar Harmanani
- •
- Genetic Algorithms, Circuits and Systems, Digital Circuits, Genetic Algorithm

This paper presents the power consumption analysis of two different routing architectures for mesh based FPGAs. The first architecture uses bidirectional Switch Box (SB) implemented using back-to-back tri-state drivers. The second one uses bidirectional SB implemented using tri-states and multiplexers. This paper highlights and experimentally demonstrates the benefit that can be reached by using multiplexers instead of back-to-back tri-state. In fact, total power consumption is reduced by around 23.5% with 0,13 µm technology which provides transistor with low leakage power and realizes 47% power savings with 0,18 µm technology. This benefit is due to a reduction in term of leakage power consumed by routing resource.

- by Habib Mehrez
- •
- Computer Architecture, Architecture, FPGA, Routing

Routing and wavelength assignment (RWA) is an important problem that arises in wavelength division multiplexed (WDM) optical networks. Previous studies have solved many variations of this problem under the assumption of perfect conditions regarding the power of a signal. In this paper, we investigate this problem while allowing for degradation of routed signals by components such as taps, multiplexers, and fiber links. We assume that optical amplifiers are preplaced. We investigate the problem of routing the maximum number of connections while maintaining proper power levels. The problem is formulated as a mixed-integer nonlinear program and two-phase hybrid solution approaches employing two different heuristics are developed.

- by maher ali
- •
- Heuristics, Nonlinear Optics, Integer Programming, Optical Amplifiers

The impact of in-band crosstalk on the transmission performance of optical cross-connects, incorporating (de)multiplexers and space switches, is studied. A statistical description of the receiver decision variable that yields a performance analysis in good agreement with experiment is given. Bit error rate and power penalties are calculated using the so-called saddlepoint approximation which is numerically simple and gives accurate results.

- by Eduward Tangdiongga
- •
- Approximation Theory, Distributed Computing, Statistical Analysis, Modeling

abstract Highly dense two-dimensional periodic arrays of nano-scaled silicon pillars present the capacity for acting as photonic crystals which can mould, manipulate and guide light. We demonstrate finite element modelling of silicon pillars based photonic crystals and their effective use in applications like waveguides, multiplexers and switches. The optical wave propagation through these structures was thoroughly simulated and analysed, confirming their high efficiency. Later the fabrication of highly periodic two-dimensional arrays of ...

- by HAIDER BUTT
- •
- Engineering, Materials Science, Photonic Crystals, Liquid Crystals

This paper address the problem of testing the configurable modules that integace the global interconnect and the logic cells of SRAM-based FPGAs. The Configurable Interjace Modules (CIMs) are assumed to be implemented with FPGA multiplexers but the resiilts can be easily extended to any v p e of interjace module. First, it is demonstrated that a n address bit Configurable Interjace Multiplexer requires N=2n test configurations considering a stuck-at as well as a functionnal fault model. Second, a logic cell with a set of k input Configurable Interjace Modules with n address bits is analysed and it is proven that the set of CIMs can be tested in parallel making the number of required test configurations equal to N=2". Third, it is shown that the complete circuit i.e. a mXm array of sets of k Con$gurable Interface Multiplexers with n address bits can be tested with only N=2" test configurations using the XOR tree and shift register structures.

Multi-valued logic is positioned as a coming generation technology that can execute arithmetic functions faster and with less interconnect than binary logic. Furthermore, nonbinary data storage would require less physical space than... more

- by Tanay Chattopadhyay
- •
- Optical Switch, Data storage, Polarization, Optical physics

A Josephson instruction read-only memory unit (IROU) has been demonstrated. The IROU, which is composed of a 10-bX 128word ROM plane, a 6-64 decoder, two multiplexers, and several buffers, has a function of storing a program for the Josephson computer ETL-JC1. The ROM plane has been designed using two-junction dc-SQUID type ROM cells, in which the ZERO ROM cell has no junction and no Superconducting loop and the ONE ROM cell has a damping resistor. The peripheral circuits have been designed using a 4JL family of OR, AND, INVERT, and AMP gates. The IROU chip was fabricated using a Nh/AIO, /Nb Josephson tunnel junction IC technology with a 3-pm design rule. There were 1280 ROM cells and 789 4JL gates integrated on the 5-mmx3.45-mm chip. All 128 words of the ROM plane could be read with the total power dissipation of 1.63 mW. The minimum total access time was measured to be 390 ps.

- by Masahiro Aoyagi
- •
- Memory, Programming, Damping, Josephson Junctions

In order to make optimum use of expensive and vulnerable spectrometers in the industrial environment, it is desirable to obtain spectra from as many samples and/or spatially-separated sampling positions as possible using one spectrometer. This may be achieved by consecutive sampling; however, simultaneous sampling is possible if a suitable multiplexing scheme is devised. An outline design is presented for a multiplexed spectrometer capable of simultaneous acquisition of multiple sample spectra. Optical or electrical signals from an arbitrary number of individual samples are encoded by presenting them in various combinations to a single spectrometer or other signal detector. The switching of the signals may be dictated by the coefficients of the Hadamard S-matrix of the appropriate order; spectra of the individual samples may then be recovered by an inverse Hadamard transform. The method described, although general, is particularly suited to IR and Fourier transform Raman spectroscopy.

- by Kevin M Wright
- •
- Design, Raman Spectroscopy, Instrumentation, Conception

- by Kevin Wright
- •
- Design, Raman Spectroscopy, Instrumentation, Conception

The effect of guard band (GB) on the performance of 40 Gb/s Absolute Polar Duty Cycle Division Multiplexing (AP-DCDM) is investigated and reported. It is demonstrated that the spectral width occupied by 40 Gb/s AP-DCDM with GB is 100 GHz (with minimum spectral efficiency of 0.4 b/s/Hz) whereas, this value can be reduced to around 80 GHz for AP-DCDM without GB (with minimum spectral efficiency of 0.5 b/s/Hz). In addition to better spectral efficiency, this amount of saving in the spectral width leads to ~ 60 ps/nm improvement in chromatic dispersion tolerance.

Seperti yang sudah diketahui bahwa pada jaman saat ini teknologi berkembang sangat cepat. Bermacam alat dihasilkan saat ini, hampir semua alat yang berfungsi di gunakan dengan energi listrik sudah menggunakan rangkaian yang digital. Saat ini rangkaian elektronika digital sudah menjadi suatu barang yang tidak aneh lagi. Rangkaian digital sudah ada di mana-mana dan berhubungan dengan rangkaian elektronika analog untuk membentuk rangkaian elektronik yang lebih pintar, cepat, dan tepat dalam penggunaan. Dan rangkaian inilah yang menjadi sebuah hubungan di antara sebuah gerbang logika. dalam elektronik, telekomunikasi, dan jaringan komputer, multiplexer adalah istilah yang digunakan untuk menunjuk ke sebuah proses di mana beberapa sinyal pesan analog atau aliran data digital digabungkan menjadi satu sinyal. Tujuannya adalah untuk berbagi sumber daya yang mahal. Contohnya, dalam elektronik, multiplekser mengijinkan beberapa sinyal analog untuk diproses oleh satu analog-to-digital converter (ADC), dan dalam telekomunikasi, beberapa panggilan telepon dapat disalurkan menggunakan satu kabel. Dalam komunikasi, sinyal yang telah dimultiplekser disalurkan ke sebuah saluran komunikasi, yang mungkn juga merupakan medium transmisi fisik. Multiplekser membagi kapasitas saluran komunikasi tingkat-rendah menjadi beberapa saluran logik tingkat-tinggi, masing-masing satu untuk setiap sinyal pesan atau aliran data yang ingin disalurkan. Pengertian Multiplexing adalah istilah umum yang digunakan untuk menggambarkan operasi pengiriman satu atau lebih sinyal analog atau digital melalui saluran transmisi umum pada waktu atau kecepatan yang berbeda dan dengan demikian, perangkat yang kita gunakan untuk melakukan hal itu disebut Multiplexer. Multiplexer, disingkat menjadi "MUX" atau "MPX", adalah sirkuit logika kombinasional yang dirancang untuk mengalihkan salah satu dari beberapa jalur input melalui jalur output tunggal yang umum dengan penerapan sinyal kontrol. Multiplexer beroperasi seperti sakelar rotari ganda posisi kerja sangat cepat yang menghubungkan atau mengendalikan beberapa saluran input yang disebut "saluran" satu per satu ke keluaran. Multiplexer, atau MUX, dapat berupa sirkuit digital yang dibuat dari gerbang logika berkecepatan tinggi yang digunakan untuk beralih data digital atau biner atau dapat berupa tipe analog menggunakan transistor, MOSFET, atau relay untuk mengalihkan salah satu dari tegangan atau input saat ini ke satu output. Jenis perangkat multiplexer yang paling dasar adalah dari sakelar putar satu arah seperti yang ditunjukkan.

- by Muhammad Fahrul
- •
- Multiplexers

- by Joerg Bauer
- •
- Information Society, Video, Optical Switch, Optical switching

All-fiber acousto-optic (AO) devices such as frequency shifters, phase, intensity and polarization modulators, tunable filters and multiplexers have been developed in the last decade mostly for their importance in fiber optic communication systems. However they can equally have potential uses in bio sensing and fiber based biomedical systems. We present the design, construction and performance of a number of all-fiber and fiber compatible acousto-optic modulators that particularly phase and polarization modulators and will address their potential uses in biomedicine. Among these components and devices, an all-fibre phase modulator acts on the phase of optical fields that propagate down the fibre core. To enhance the phase modulation, the acoustic energy is focused into the fiber core using an acoustic lens. Another high efficiency birefringence (or polarization) modulator was demonstrated that is designed to operate at the acoustic resonance frequency of the fiber. Fiber compatible devices were built using gradient index (GRIN) lenses that can couple the light into a fiber or between two fibers. Diffraction based and polarization GRIN modulators were demonstrated and AOMs of in-fiber gratings as well as ones made from glasses that exhibit large AO figure of merit. As a high frequency polarization, phase, intensity or wavelength modulators these devices have a great potential for use in polarimetric imaging, scanning of a fiber-optic OCT system, tuning the wavelengths in miniature hyperspectral imaging systems and sensors or for frequency-domain OCT.

- by Ibrahim Abdulhalim
- •
- Fiber Optics, Polarimetry, Communication System, High Frequency

Monolithically-integrated semiconductor optical amplifiers (SOAs) have the potential for enabling high-speed and lowcrosstalk optical switches in reconfigurable optical add-drop multiplexers (ROADMs). Using integrated 4x4 switches as the building blocks for large-scale ROADMs, instead of 2x2 switches, will reduce alignment issues and assembly steps during manufacturing. The switch is based on SOAs, quantum well intermixed (QWI) passive 1x4 MMI splitters/combiners, and total internal reflection mirrors. We present the results of the 4x4 switch design, for a switch of 5.3 mm x 3.5 mm in size, with estimated total excess on-chip losses of 23 dB.

- by Trevor Hall
- •
- Manufacturing, Optical Switch, Reflection, Optical switching
- by Trevor Hall
- •
- Optics, Quantum Physics, Refractive Index, Optical physics
- by Trevor Hall
- •
- Optics, Quantum Physics, Silicon Photonics, Optical Waveguide
- by Rafal Dlugosz
- •
- Medical Imaging, Randomization, User Interface, Sensors