The monolithic integration of optical components with different functionalities on a single semiconductor wafer requires spatially selective control of bandgap energies. We have developed a simple, post-growth technique based on quantum well intermixing using ion implantation and rapid thermal annealing, which allows multiple selective area bandgap tailoring. Waveguide absorption spectra demonstrate that the bandgap energy can be shifted as much as 90 nm without any excess loss. By depositing a SiO₂ layer of different thicknesses in different regions as the implantation mask, quantum wells in different sections of a wafer can be intermixed to different degrees in a single implantation and annealing process. It has also been shown that the heavy-hole and light hole states in the quantum wells can become degenerate at a certain degree of intermixing, which allows the fabrication of polarization insensitive optical amplifiers and electro-absorptive switches. The performance of both active (laser, amplifier, modulator) and passive (waveguide) components produced using this technique will be presented.

We present herein a technique of fabricating grating lenses and lenslet arrays on glass by laser direct writing. Computer generated grating patterns with precision of two microns can be written directly on an ion-exchanged glass plate using a visible low-power semiconductor diode laser. The grating lens components produced by this technique have the advantages of compactness and planar integratability with other optoelectronic components. The comparison of theoretical design and experimental results of grating lenses is given. The limitation of this technique is also discussed. Good lens focusing performance is demonstrated. High efficiency gratings lenses and lenslet arrays can find applications in optical interconnection, printing, and computing systems.

We have demonstrated a complete optical data between a pair of optical transmitter (Tx) and receiver (Rx) multichip modules (MCMs) using polymer optical waveguide array as interconnect media. The Tx and Rx MCMs each has three data channels and are fabricated using conventional MCM-C technology. The components used in our MCMs include Honeywell's vertical cavity surface emitting lasers (VCSELs) at wavelength of 850 nm, and other commercial off-the-shelf Si devices such as Si detectors, laser drivers, and amplifiers. The waveguide interconnect is over 4-inch long, and includes both flexible ribbons and board integrated polymer waveguides with passively aligned connectors. The waveguides are finished with 45-degree mirrors at each end facets for interfacing with the VCSELs and the p-i-n detectors in the Tx and Rx modules, respectively. The loss of the overall optical link is less than 10 dB. We have measured a bit-error-rate of less than 10^-12 at a data rate of 1 Gbps per channel.

Blazed gratings have been identified as potential high efficient, compact, and planar waveguide couplers. The asymmetrical continuous profile of the blazed grating allocates all diffracted light into a single order and produces higher efficiency for waveguide coupling. This asymmetrical continuous profile also brings difficulty to the fabrication process. This is particularly true when the integrated optoelectronics are down-sized and simple fabrication procedures are in demand. In this paper, a binary blazed grating coupler is proposed to facilitate the fabrication process and retain a high coupling efficiency. Computer analyses of the binary blazed grating profile and diffraction distribution are given. Design and fabrication issues of a waveguide coupler are also discussed.

We report on a novel structure for differential pairs of III-V optical thyristors, which functions as an optical-to- electrical converter for incoming digital optical pulses (rather than as an opto-optical converter). This novel detector has unique properties which makes it most suitable for short-distance optical interconnects. First, it is very sensitive: we show that it is sensitive to optical pulses of only 3 femtojoule at 830 nm. This allows for the use of less efficient cheap LEDs as light-emitters. Second, we demonstrate a bitrate of 155 Mbit/s, which is appealing for inter-MCM and inter-chip interconnects. Third, the transceiver is switched with a CMOS-compatible voltage (5 V) and the electrical output signals are of the order of 0.3 V, easy to detect with a small CMOS circuitry. Fourth, the detector is compact: presently, its area is 200 micron X 160 micron, and it can be scaled down to 50 micron X 50 micron. This allows for large parallelism, e.g. thousands of interconnections per chip.

The quality of optical thin films in integrated optics was more advanced than those in optical coatings in the mid- 1970s. However, quality of today's ion beam sputtered coatings is more advanced than the films in integrated optics. This reversal appears to be application driven. Due to the heavy demand of information highway, it is believed that better quality films in integrated optics will soon catch up again. Ample illustrations will be given.

In this paper it is presented a theoretical evaluation of the following important amplifier parameters: the output mean photon number, the standard deviation, the Fano factor, the statistical fluctuation and the spontaneous emission factor for single and double pass configuration, and for forward and backward pumping schemes in quasi two level optical waveguide amplifiers. The theoretical model used to evaluate the noise characterization of an Er³⁺-doped Ti:LiNbO₃ waveguide amplifiers is based on the photon statistics master equation of the linear amplifier, closely related with EDFA model and has been modified to account for the effects of the host material. One considered a quasi two level system model and one neglected ESA due to the considered pumping wavelength. The interaction of the pump and signal photons with Er³⁺ ions in LiNbO₃ can be described using the rate equations. The simulations were performed using the small gain approximation in Er³⁺:Ti:LiNbO₃ optical waveguides. The pump was supposed in the 1480 nm range and the signal having (lambda) equals 1530 nm. The evaluation of the above mentioned parameters vs. wavelength, pump powers, etc. were also performed and commented.

Semiconductor laser performances are affected by optical feedback even at low levels. Differences between front and rear facet emission arise from optical feedback. Experimental results are discussed. To implement the usual microscopic approach a first principles calculation of coherence length for the radiation which is emitted by a system (laser device and the optical feedback source) is given, leading to a non equivocal definition of coherent and incoherent feedback, even for single mode systems. A model is built that is naturally prepared for massive parallel computation by suitably shaping microscopic processes into rules of evolution of a Cellular Automation. The results of theoretical investigations give a common framework for the wealth of experimental results otherwise looking contradictory and allow the identification of the relevant parameters.

The set of CCD structures for analog realization of main arithmetic operations such as a summing up, a subtraction, and a multiplication is presented. Using these structures it is possible to create various circuits and arrays for signal and image analog processing. Several types of these circuits and arrays are described. An analog filters with constant and random weights and Sobel's transformation circuit have been created. Some experimental results are given.

Strongly-guided 2D and 1D dielectric waveguides, which we call (dielectric) photonic wells and wires, can be used to modify the spontaneous emission properties of the active medium significantly. We will discuss how the photonic wells and wires can be used to realize efficient laser cavities. Semiconductor microcavity lasers based on photonic-well and photonic-wire structures will be described. They include the microdisk lasers, the photonic-wire lasers, and lasers with 1D photonic bandgap structures. We will discuss how with use of photonic-well or photonic-wire structures, the efficiency of capturing the spontaneous emission photons into a particular lasing mode (i.e. the spontaneous-emission coupling efficiency) can be as high as 10% to over 70%. The microdisk and photonic-wire laser realized will allow us to study spontaneous emission and lasing in low-dimensional photonic structures.

An optoelectronic smart pixel device for optically reconfigurable Boolean logic gate array is proposed. It consists of more than 4 X 10⁵ pixels used as logic gates that can operate in parallel. By setting different optical biases on pixels, every pixel is reconfigurable (to perform different kinds of logic gate operations). All kinds of logic gates can be implemented simultaneously in this device. The principle of operation and its fundamental characteristics are described in detail. The device makes fully use of the physics features of amorphous silicon photoconductor and liquid crystal and does not need the controlling architecture with very large scale integration circuits. Therefore, bigger aperture ratio, higher resolution (more than 45 lines/mm), and higher space bandwidth product are achievable.

The new optoelectronic integrated technology--wafer bonding is described. The results of wafer bonding and applications in several new types of optoelectronic devices are presented.

In this paper, physical analyses on the characterization of the electroreflectance modulator are concerned, which include quantum confined Stark effect and asymmetric Fabry- Perot cavity effect and so on. Experimental results are provided to demonstrate the properties of normally-off and normally-on devices. The developed technology is used to tune the mode to the proper position to improve the contrast ratio of modulators.

High performance 1.3 micrometers and 1.55 micrometers InGaAsP/InP strained layer quantum well (SL-QW) lasers grown by low pressure metal organic chemical vapor deposition are reported in this paper. 1.3 micrometers SL-QW lasers and 1.55 micrometers SL-QW lasers with broad area threshold current densities as low as 400 A/cm² and 450 A/cm² (at cavity length 400 micrometers ), DC-PBH stripe device threshold currents of 5 approximately 10 mA and 6 approximately 10 mA were obtained, respectively. The prediction life time of 1.3 micrometers SL-QW lasers is more than 10⁶ hrs at 25 degree(s)C, and degeneration activated energy is 0.682 eV according to the accelerate aging tests.

A general optoelectronics integrated circuit (OEIC) computer-aided analysis software--OCAP has been developed on Sun SPARC workstations. This system can be used to simulate the DC, AC and transient characteristics of OEIC which can include semiconductor laser diodes such as DH-LD, QW-LD, DFB-LD, detectors such as PIN-PD, PIN-APD, MSM-PD, PINIP two color detector, electronic devices such as diode, B/T, HBT, MESFET, and other basic elements such as resistance, capacitance, inductance, individual source, and controlled source.

TE-pass integrated optical waveguide polarizers have been made in Z-cut, T-propagating LiNbO₃ using titanium indiffusion in conjunction with proton exchange. The two exchanged regions are adjacent to the Ti-indiffused waveguide on both sides and at the output end of the sample. In the proton-exchanged regions, (Delta) n_e > 0, (Delta) n_o < 0. Thus, the TM mode is radiated into the substrate. The polarizer operating at (lambda) equals 1.3 micrometers exhibits an extinction ratio > 53 dB and fiber-waveguide- fiber excess loss is 4 dB.

We present the ultrashort electromagnetic pulses radiation system. The radiation antenna device are both illuminated by picosecond optical pulses, and the other same device for reception. Fabricated on a GaAs substrate, the antenna device consists of double-shottky-band and quasi-exponential antenna. We have obtained broad-band electromagnetic pulse radiation.

We propose an adiabatic all-optical switch composed of an Y- branch, Ag for Na ion-exchanged glass waveguide covered by PDMA film. We employ effective index method to analyze the property of propagation of the waveguide and give the reasonable parameters of the waveguide structure. For demonstration of nonlinear switching behaviors in the device, we employ a beam propagation method to simulate optical field propagation.

A new version of thermo-optical modulator has been presented here. The device is a pair of single-mode parallel channel waveguides on glass substrate by using K-ion exchanging technique. A Ti-film strip heater is set on the separation to control the coupling coefficient between the two parallel waveguides. The deduced expression shows that the change of coupling coefficient is approximately proportional to the change of temperature. The output of coupler varies with sine square in which phase angle is linearly related to change of the index. The phase angle is controlled by thermo-optical effect in our study. The device is designed to operate at wavelength 632.8 nm, the measured modulation depth of the device is as high as 90%.

The linewidth broadening of Distributed Feedback (DFB) semiconductor lasers under direct modulation become more and more serious with the increase of modulating data rate. So it is important to investigate externally modulated transmitter module whose dynamic linewidth is the same as its static linewidth. The integrated module including DFB-LD and LN modulator reported here has a 3 dB-bandwidth of 3.8 GHz, 4 V drive voltage, and operating wavelength at 1548 nm, its linewidth is about 100 MHz measured by Gated Delay Self Homodyne and output power is 200 (mu) W. It has been used in optical transmission system and shows good characteristics.

The paper presented a kind of triangular non-Bravais lattice which constructed from dielectric cylinders in air can open an absolute photonic band gap for common to E and H polarizations. The conditions for the appearances of absolute photonic band gap were discussed, and the potential applications of this lattice were also discussed.

Anneal proton-exchanged planar waveguides on LiNbO₃ are investigated on aspect of crystallography and of optical properties. The strains and stress on crystalline lattices of LiNbO₃ due to proton exchange and annealing respective are measured by DDX (Double Diffraction of X-ray) and IR spectrometer. We study theoretically and experimentally the induced photoelastic and piezoelectric effects inside exchanged layer to explore mechanism of anneal. That demonstrates annealing technology being a efficient compensation permits to ameliorate the quality of waveguide and deduced optical propagating loss.

1.3 micrometers Ti:LiNbO₃ optical waveguide frequency demultiplexer with four-channel electrical tune is presented. The device consists of the single mode waveguide which has a pair of modulated electrodes and a DBR reflector. By changing the voltage added to the electrodes, the four different optical frequencies can be selected, because of the waveguide reflective index change induced by electro-optic effect.

A method of integrated acousto-optic processor conceived for GPS signal acquisition is presented. Once the Doppler shift is resolved, the time of arrival is obtained quasi- instantaneously in this system. It is estimated an acquisition time of at most 1 ms. In this paper, the principle, design, structure of the integrated AO correlator are mainly described.

In this paper, the asymmetric X-junction is applied in the GaAs Mach-Zehnder optical switch instead of the traditional Y-branch and a 1 X 4 switch array is designed and fabricated. The basic mechanism of the asymmetric X-junction is briefly narrated. The considerations for the device's designing and the fabrication process are also presented. The switch unit in this device operating at 1.15 micrometers has a switching voltage of 12 V and a crosstalk of less than -20 dB. The propagation loss in the waveguide of this device is about 7 dB/cm.

1.3 micrometers and 1.55 micrometers InGaAsP/InP quantum well (QW) light emitting diodes (LEDs) with narrow beam divergence grown by low pressure metal organic chemical vapor deposition are reported in this paper. 1.3 micrometers and 1.55 micrometers QW LEDs with beam divergence of 30 - 45 degree, chip output power of more than 300 (mu) W and 200 (mu) W, and single mode fiber output power of 60 (mu) W and 40 (mu) W were obtained by optimizing the device structure parameters.

Optical waveguide geodesic lens that has no aberration and no curvature singularity has been developed. Quoting the function form of generating line from our previous work, singularities at the transition section's both ends were eliminated effectively. The lens was designed and fabricated. Measurements show that the geodesic lens is free of spherical aberration in the effective aperture zone of 8 mm, and the diffraction spot ranges in 3.3 micrometers versus the incident beam width of 4.78 mm.

To obtain a micro optic rotation sensor (MORS), a passive ring resonator (PRR) based on channel waveguide was designed and investigated. The waveguide structure of the resonator includes a ring waveguide as well as two directional couplers. The theoretical resolution and transfer functions of the MORS are discussed, and the PRR parameters are determined. According to the sensitivity requirement, the PRR frequency detecting system is discussed, and different detecting schemes are compared.

We present a new approximation for obtaining the analytical dispersion relations of planar waveguides with arbitrary index profile of practical interest. In our method, two substantial improvements over the conventional WKB method are presented. The numerical comparisons show a good accuracy of the results even for a single-mode waveguide or close to the turning point.

The planar waveguides have been successfully fabricated using polyimide as host in guest-host thin films. The stability of the poled film by corona-onset poling at elevated temperature is investigated. By measuring small changes in the refractive-index anisotropy, the optical waveguiding technique is demonstrated to be a sensitive measure of the poling-induced order. Second-harmonic generation experiments are performed to measure the decay of second-order nonlinearity.

The dynamics of the optical induced refractive index change and the absorption change in GaAs film is studied using femtosecond transmission and reflection spectroscopy. A rapid variation of the optical induced refractive index and an increased optical induced absorption are observed. These phenomena are interpreted with the band filling and the bandgap shrinking effect of the excited carriers.

The effects of metal-cladding on the cutoff condition of step and graded index optical waveguides are analyzed by the perturbation method in this paper. The cutoff thickness of metal-cladding waveguide is thicker than the waveguide with the dielectric (air) cladding. For step index profiles optical waveguides, the cutoff thickness of TE₀ mode is more 7% than the case with air cladding, and TM₀ mode is 26%.

In this paper, an integrated optical chip fabricated on the substrate of GaAs for optical fiber gyroscope is completed. The chip is composed of polarizer, beam splitter, phase modulator and single-mode waveguide. The chip is much smaller than that fabricated on LiNbO₃, the size is 25 mm X 0.5 mm. The extinction ratio of the polarizer is designed to be better than 40 dB. Two light spots coming out of the beam splitter has been monitored. The half wave voltage of the phase modulator is below 5 v.

Self-electrooptic effect devices (SEEDs) and GaAs field- effect transistors (FETs) are used to form smart pixels. A 8 X 4 array of simple field-effect transistor-self- electrooptic effect device (FET-SEED) smart pixels has been fabricated by interconnecting a SEED chip and a GaAs FET chip on a printed circuit board. The smart pixel consists of a detector SEED, a modulator SEED, and a simple GaAs FET amplifier. An optical system have been designed and constructed to demonstrate the smart pixels. The operational principle of the smart pixels is also described.

Fabrication and measurement of monolithic integrated waveguides with three parts, that is transmissive grating and two spheroidal geodesic lenses on Ag⁺ - Na⁺ ion exchanged glass substrate, is reported. The monolithic waveguides are measured using diode laser of 1.3 micrometers and the Bragg diffraction efficiency of grating of waveguides is 40%.

A chirped grating was fabricated on CdSxSe1-x doped glass waveguide characterized by intensity dependent refractive indices to use for all-optic tunable interconnection. The focal line move of 80000 nm was observed when the power density of the guided wave was changed. Five possible locations of the focal line for optical interconnection are determined.

We fabricated a digitized dual-frequency coupling gratings. And it was demonstrated experimentally that a two level digitization of the analog profile performs the waveguide interference between two free space waves.

The noise characteristics of gain-clamped EDFA by using a feedback loop was investigated theoretically and experimentally. It is proposed for the first time that the gain-clamped EDFA can be operated with considerable low noise figure if the operation point, i.e., the degree of the feedback and the laser loop structure was selected properly.

Wavelength-division-multiplexing technology is now recognized as one of the key technologies in optical communication systems. Because it can greatly enhance the capacity of the communication systems. And the optical wavelength-division-multiplexing devices are the key parts in the wavelength-division-multiplexing technology. The authors have integrated a pair of lens and a grating on a piece of K₇ glass substrate in order to achieve the optical wavelength-division-multiplexing function. The optical wavelength-division-multiplexing's wavelength ranges from 1.10 micrometers to 1.55 micrometers and its central wavelength is 1.3 micrometers . The channel's interval is 40 nm and the available channels number >= 12. The insertion losses <EQ 8 dB and the channel's crosstalk is better than -20 dB. The waveguide is K⁺ ion exchange waveguide.

The study on the design of optical waveguide geodesic lenses that have no aberration and no singularity in curvature was reported. In theoretical design, the general analytical method for designing a perfect geodesic lens, which was first presented by Sottini et al., was improved. In this paper, a suitable function of meridian in transitional zone was chosen deliberately to make sure that the meridian has a continuous second order derivative. A particular solution of nonsingular in curvature, aberrationless, and non-spherical optical waveguide geodesic lens was presented. This kind of geodesic lenses was designed and fabricated with single point diamond machining and high temperature Ti-diffusing in LiNbO₃. Through experimental measurement, it was shown that the spherical aberration was eliminated in 8 mm effective aperture and that the focal spot size was 3.3 mm for 4.78 mm stop size.

A 4-bit electrooptic analog-to-digital converter which utilizes an array of Fabry-Perot interferometric modulators composed of anneal proton exchanged LiNbO₃ straight channel waveguide with two parallel reflection end faces is reported. The principles of operation of the Fabry-Perot analog-to-digital converter are described. The design parameters, fabrication procedure, the measurement set-up and first-fruits of the experimental model are reported.

In this paper, a novel hybrid passive component for EDFA was reported. This component integrated the 1550 nm polarization independent optical isolator and the 980/1550 nm pump WDM within a single compact case, and realized the reduction of insertion loss, cost and package size. The following techniques were adopted in fabricating this component: (1) high efficiency beveled end-face off-axis coupling between twin core ferrule and GRIN rod; (2) the pump WDM is based on GRIN rod and optical interference filter; (3) the optical polarization independent isolator using birefringence wedge, etc. This component was packaged in an ordinary isolator case as small as (Phi) 8 X 40 mm. The insertion loss of signal is less than 0.9 dB; the insertion loss of pump is less than 0.8 dB; the isolation of the built in isolator is more than 42 dB with +/- 15 nm pass-band and the return loss is more than 50 dB. This component has shown very stable performance against the environmental changes. It had been applied to a single forward pumped EDFA module, and has achieved the following good performance: more than 29 dB small signal gain, less than 5 dB noise figure, more than +10 dBm output power. The EDFA module has the dimension largely reduced to 15 X 100 X 130 mm.

A new version of the semi-vectorial Finite-Difference Beam Propagation Method equation in cylindrical coordinates is introduced to analyze and design the small radius of bent wave-guide in which the strong lateral confinement keeps the low-loss of radiation. The slowly varying envelope wave is finite-differenced in taking into account of the discontinuities of the electric field components across any arbitrary distribution of internal dielectric interfaces under the approximation of no coupling between the different polarized components. This version of equation can model the polarization effect of optical field and gives good results for the power loss rates even at radii < 100 micrometers . Using the implicit alternating method, the algorithm of 3D-wave equation is improved to carry out very stably and quickly.

Optical signal distributions through side-emitting ports along a polymer optical fiber are demonstrated using etched micro-mirrors. Low-cost serial and parallel mirror fabrication processes are described. Near uniform light distributions through as many as 200 such output ports along a single fiber of 0.75 mm diameter and 0.485 numerical aperture are obtainable. A 4 X 16 plastic array coupler for fiber-to-fiber interconnections was fabricated. The fabricated couplers have maximum coupling efficiencies of up to 84.7% and 91.4% using, respectively, the total internal reflection type and metal coating type micro-mirrors. The coupling uniformity for the two cases are 84% and 76%, respectively. The coupling efficiency and its relation to misalignments are studied.

In this paper, we represent our effort to construct an optoelectronic interconnection layer for high-speed optical clock signal distribution in a Cray supercomputer board. The optoelectronic interconnection layer under investigation employs optical channel waveguides and 3 dB waveguide splitters in conjunction with surface-normal waveguide couplers. The difficulties associated with the complicated 3D multiple alignments are significantly reduced by the surface-normal fanout beams and the unique planar device feature. 1-GHz clear optical clock signal is demonstrated experimentally with a guided-wave interconnection length of 45 cm. Some new techniques to fabricate large-area optical channel waveguides and surface-normal waveguide grating couplers are also presented.

A compact and affordable photonic true-time-delay lines for phased-array antenna applications using multiplexed substrate guided wave propagation is reported. Optical signals are fed into the device through surface normal to substrate holographic grating couplers recorded on DuPont HRF-600 photopolymer films. Various optical delays are obtained through optical fanouts at consecutive substrate bouncing positions through holographic output couplers. Design issues on the TTD architecture and the making of slanted holographic grating couplers with controllable diffraction efficiencies are discussed. The non-uniform intensity fanout problem, which is common for substrate guided approach due to cascaded propagations, is addressed and an 1D 8 delay lines with fanout intensity fluctuation within 10% is demonstrated. As a test for ultra-wideband operation, 25 GHz microwave signals, generated through optical heterodyne technique, are made to transmit through the device and subsequently detected with a signal-to-noise ratio of 20 dB.

We demonstrate the performance of InGaAs/InP multiple quantum well modulators for fiber access applications. On/off contrast ratios in reflectivity are 22:1 with a 10:1 level extending over a 26 nm bandwidth at 1.55 micrometers . The methodology to produce such devices is described within.

We present a numerical computation technique on analyzing Bragg diffractions by superimposed transmission phase gratings. It can account for diffractions by any number of superimposed gratings with symmetric and asymmetric diffraction geometries. The angular and wavelength selectivity curves are shown to be still (sinc)² functional dependent in the examples provided. The selectivity bandwidth on one diffraction angle is found to depend on other superimposed diffraction gratings selected. The simple computation technique should be suitable for design engineers to establish grating index combinations prior to experimental implementation of optical beam splitting components.