Showing papers in "IEEE Photonics Technology Letters in 1995"
TL;DR: In this article, the authors demonstrate integration of GaAs-AlGaAs multiple quantum well modulators to silicon CMOS circuitry via flip-chip solder-bonding followed by substrate removal.
Abstract: We demonstrate integration of GaAs-AlGaAs multiple quantum well modulators to silicon CMOS circuitry via flip-chip solder-bonding followed by substrate removal. We obtain 95% device yield for 32/spl times/32 arrays of devices with 15 micron solder pads. We show operation of a simple circuit composed of a modulator and a CMOS transistor. >
291 citations
TL;DR: In this paper, an all-fiber Mach-Zehnder interferometer with photo-induced Bragg gratings was used to drop/insert a single wavelength channel from/into a multiple-wavelength transmission link with 100 GHz channel-spacing at 1550 nm.
Abstract: A wavelength multiplexing/demultiplexing device is fabricated and used to drop/insert a single wavelength channel from/into a multiple wavelength transmission link with 100 GHz channel-spacing at 1550 nm. The device consists of an all-fiber Mach-Zehnder interferometer with photoinduced Bragg gratings. The following performances were measured: extraction/coupling efficiency =99.4%, excess loss 20 dB, and return loss >23 dB. >
219 citations
TL;DR: Injection locking of a semiconductor laser can significantly improve the broadband modulation characteristics as mentioned in this paper, by adjusting the frequency offset between the master laser and the slave laser, improved modulation bandwidth or flatness of the modulation response can be emphasized.
Abstract: Injection locking of a semiconductor laser can significantly improve the broadband modulation characteristics. By adjusting the frequency offset between the master laser and the slave laser, improved modulation bandwidth or flatness of the modulation response can be emphasized. The improved modulation characteristics are accompanied by reduced broadband relative intensity noise. Our calculations predict that the parasitic-free modulation bandwidths can be enhanced above the theoretical limit for the free-running laser. >
197 citations
TL;DR: In this article, the authors report on the room-temperature continuous-wave operation of vertical-cavity lasers operating at 1.54 /spl mu/m. The devices use a 7 strain-compensated quantum-well active layer sandwiched between two Al(Ga)As-GaAs quarter-wave mirrors joined by wafer fusion.
Abstract: We report on the room-temperature continuous-wave operation of vertical-cavity lasers operating at 1.54 /spl mu/m. The devices use a 7 strain-compensated quantum-well active layer sandwiched between two Al(Ga)As-GaAs quarter-wave mirrors joined by wafer fusion. Five device sizes between 8 and 20 /spl mu/m were found to operate continuously at room temperature (23/spl deg/C), The lowest room-temperature continuous-wave threshold current of 2.3 mA was measured on an 8-/spl mu/m diameter device, while the highest continuous-wave operating temperature of 33/spl deg/C was measured on a 12-/spl mu/m device. >
188 citations
TL;DR: In this paper, the authors show that transparent optical networks corrupted by interferometric signal-crosstalk beat noise from only 8 crosstralk fields, which is the number of fields required to generate in-band signal-to-noise.
Abstract: As transparent optical networks are scaled up in size, stringent constraints must be placed on the in-band crosstalk generated by their components. Measurements show that transparent networks corrupted by interferometric signal-crosstalk beat noise from only 8 crosstalk fields require component crosstalk levels >
180 citations
TL;DR: In this article, a novel local access network, LARNet, is proposed and demonstrated using a multifrequency laser whose wavelength COMB94 is matched to that of a passive waveguide router in the remote node, is used as a downstream signal source.
Abstract: A novel local access network, LARNet, is proposed and demonstrated. A multifrequency laser, whose wavelength COMB94 is matched to that of a passive waveguide router in the remote node, is used as a downstream signal source. A 1.3-/spl mu/m commercially available LED provides the upstream signal. LARNet solves a major problem of WDM networks, the spectral alignment between the optical wavelengths of different channels. Furthermore. The expensive components are shared among all subscribers. Our measurements indicate that aggregate rates of 2 Gbps downstream and 155 Mbps upstream are feasible. >
145 citations
TL;DR: In this paper, an electrically-pumped, vertical-cavity, surface-emitting laser (VCSEL) using an AlAs oxide-GaAs DBR above the AlGaAs-GaA-InGaAs gain region was described.
Abstract: An electrically-pumped, vertical-cavity, surface-emitting laser (VCSEL) using an AlAs oxide-GaAs DBR above the AlGaAs-GaAs-InGaAs gain region and a conventional AlAs-GaAs DBR below is described. By selective oxidation, devices with current flow apertures of different areas are fabricated, and in 8-/spl mu/m-square devices, threshold currents as low as 0.22 mA are achieved. Being the first electrically-pumped VCSEL to utilize the oxide-based DBR, it demonstrates that the oxide-based DBR is of sufficient quality to realize submilliampere threshold currents. >
138 citations
TL;DR: In this paper, the integration of GaAs-AlGaAs multiple quantum well modulators directly on top of active silicon CMOS circuits is presented, which enables optoelectronic VLSI circuits to be achieved and also allows the design and optimization of the CMOS circuit to proceed independently of the placement and the bonding of surface normal optical modulators to the circuit.
Abstract: We accomplish the integration of GaAs-AlGaAs multiple quantum well modulators directly on top of active silicon CMOS circuits. This enables optoelectronic VLSI circuits to be achieved and also allows the design and optimization of the CMOS circuits to proceed independently of the placement and the bonding of surface-normal optical modulators to the circuit. Using this technique, we demonstrate operation of a 0.8 micron CMOS transimpedance receiver-transmitter circuit at 375 Mb/s. >
133 citations
TL;DR: In this article, a surface micromachined Fabry-Perot cavity used as a pressure sensor has been fabricated using standard IC technology using dielectric film stacks consisting of layers of silicon dioxide and silicon nitride as mirrors.
Abstract: A surface micromachined Fabry-Perot cavity used as a pressure sensor has been fabricated using standard IC technology. Dielectric film stacks consisting of layers of silicon dioxide and silicon nitride were used as mirrors. Polysilicon was used as a sacrificial layer that was then removed to form an air gap cavity. The Fabry-Perot sensor was optically interrogated using a multimode optical fiber. The measured response of the sensor agrees well with theoretical simulation, which takes into account the averaging effect caused by the shape of the deflected mirror in the cavity.
132 citations
TL;DR: In this paper, a method for the synthesis of optical filters consisting of a cascade of N-coupled rings is presented based on the definition of a polynomial whose roots are the zeros of the channel-dropping transmittance characteristic and provides directly the ring electrical lengths and the mutual coupling coefficients.
Abstract: A method for the synthesis of optical filters consisting of a cascade of N-coupled rings is presented. The procedure is based on the definition of a polynomial whose roots are the zeros of the channel-dropping transmittance characteristic and provides directly the ring electrical lengths and the mutual coupling coefficients. A design example of a Chebyshev-type 6-ring bandpass filter is presented.
130 citations
TL;DR: In this paper, the first fabrication and measurement of travelling-wave photodetectors is reported, which have bandwidths as high as 172 GHz, the highest reported for a p-i-n photodeter, and bandwidth efficiency as large as 76 GHz.
Abstract: Results of the first fabrication and measurement of travelling-wave photodetectors are reported. The devices have bandwidths as high as 172 GHz, the highest reported for a p-i-n photodetector, and bandwidth-efficiency products as large as 76 GHz, the largest reported for any photodetector without gain. Comparisons with vertically illuminated and waveguide photodetectors fabricated on the same wafer establish the superior performance of travelling-wave photodetectors. Microwave loss on the travelling-wave photodetector structure is identified as a bandwidth limitation. >
TL;DR: In this paper, a fiber-optic finite impulse response filter with continuously tunable unit time delays is developed and studied, which consists of eight taps with progressively longer segments of high-dispersion fiber, but completed with dispersion-shifted fiber to nominally identical overall lengths.
Abstract: A fiber-optic finite impulse response filter with continuously tunable unit time delays is developed and studied. The filter consists of eight taps with progressively longer segments of high-dispersion fiber, but completed with dispersion-shifted fiber to nominally identical overall lengths. The time delays through each tap are tuned by varying the wavelength of the optical carrier. The constructed 8-tap filter exhibits bandpass characteristics with a Q of 30. The bandpass band is continuously tuned over a full octave from under 9 GHz to over 18 GHz with a single low-voltage control signal that demonstrates the technique's applicability to adaptive systems. >
TL;DR: In this paper, a laser oscillation from self-organized In/sub 0.5/Ga/sub sublevel of In/Sub 0.4/As quantum dots is demonstrated for the first time by electroluminescence and diamagnetic energy shift measurement.
Abstract: A laser oscillation from self-organized In/sub 0.5/Ga/sub 0.5/As quantum dots is achieved at 80 K by current injection. Lasing at a three-dimensionally quantum confined sublevel of the In/sub 0.5/Ga/sub 0.5/As quantum dots is clearly demonstrated for the first time by electroluminescence and diamagnetic energy shift measurement. The results predict the possibility of ultra-low threshold current operation of quantum dot lasers.
TL;DR: In this article, the authors report the high yield fabrication and reproducible performance of selectively oxidized vertical-cavity surface emitting lasers. Butler et al. showed that linear oxidation rates of AlGaAs without an induction period allows reproducible fabrication of buried oxide current apertures within monolithic distributed Bragg reflectors.
Abstract: We report the high yield fabrication and reproducible performance of selectively oxidized vertical-cavity surface emitting lasers. We show that linear oxidation rates of AlGaAs without an induction period allows reproducible fabrication of buried oxide current apertures within monolithic distributed Bragg reflectors. The oxide layers do not induce obvious crystalline defects, and continuous wave operation in excess of 650 h has been obtained. The high yield fabrication enables relatively high laser performance over a wide wavelength span. We observe submilliamp threshold currents over a wavelength range of up to 75 nm, and power conversion efficiencies at 1 mW output power of greater than 20% over a 50-nm wavelength range. >
TL;DR: In this article, a single-mode optical waveguide at 1300 nm has been fabricated from the organic polymer benzocyclobutene, using a 535 rmb photodefinable resin for forming the core of the waveguide, allowing the waveguides to be processed in a fashion similar to a negative photoresist.
Abstract: Single-mode optical waveguides at 1300 nm have been fabricated from the organic polymer benzocyclobutene. This material system utilizes a 535 rmb photodefinable resin for forming the core of the waveguide, allowing the waveguides to be processed in a fashion similar to a negative photoresist. The processing conditions required for the fabrication of single-mode benzocyclobutene optical waveguides are presented. With the measured losses in the waveguide equal to 0.81 dB/cm at 1300 nm, this material system is suitable for use in a variety of optical interconnect applications. >
TL;DR: Carrier subtraction from a weakly modulated optical signal is proposed, analyzed, and demonstrated in this paper to improve fiber-optic system efficiency, achieving an improvement of 9-13 dB in link loss from 1 to 25 GHz.
Abstract: Carrier subtraction from a weakly modulated optical signal is proposed, analyzed, and demonstrated to improve fiber-optic system efficiency. For constant photodetector current, an amount of carrier suppression results in an equal amount of RF gain. Improvement of 9-13 dB in link loss from 1 to 25 GHz is measured using a Fabry-Perot filter operating in the reflection mode. Measured induced harmonic distortion agrees with predicted values. >
TL;DR: In this article, a Fabry-Perot microinterferometer with a suspended movable membrane was demonstrated, which exhibits a 32nm tuning range around the 920-nm center wavelength for 0-14 V applied bias and FWHM linewidths near 3 nm.
Abstract: Fabry-Perot microinterferometer is demonstrated that combines a GaAs-AlAs vertical cavity with a suspended movable membrane. Electrostatic displacement of the gold/silicon nitride membrane allows for broad and continuous wavelength tuning of the cavity resonance formed by the combination of the GaAs cavity and the air gap below the membrane. The device exhibits a 32-nm tuning range around the 920-nm center wavelength for 0-14 V applied bias and FWHM linewidths near 3 nm; this corresponds to membrane deflections of up to 0.27 /spl mu/m. Such structures provide the foundation for wavelength selective photodiodes, light emitters, and lasers in which the active wavelength is under voltage control. >
TL;DR: In this article, the fabrication and characterization of wide-band Fabry-Perot-like resonators in optical fiber has been reported, with free spectral ranges between 0.09 nm and 11.27 nm.
Abstract: We report the fabrication and characterization of wide-band Fabry-Perot-like resonators in optical fiber. Using Bragg gratings with variable detuning, resonators that operate ever a wavelength span in excess of 140 nm have been produced, with free spectral ranges between 0.09 nm and 11.27 nm. Numerical and experimental results for two typical resonators are presented, showing good agreement between the two. >
TL;DR: In this paper, high-concentration Er/sup 3+//Yb/Sup 3+/ co-doped silica waveguide amplifiers are numerically analyzed. And the authors demonstrate the possibility of fabricating short and high-gain integrated optical amplifiers; it is shown that net gain as high as 3 dB/cm can be obtained.
Abstract: High-concentration Er/sup 3+//Yb/sup 3+/ co-doped silica waveguide amplifiers are numerically analyzed. With optimized rare-earth concentrations the effect of Er/sup 3+//Er/sup 3+/ ion-pairs can be neglected and each Er/sup 3+/ ion can be assumed to be paired only to the surrounding Yb/sup 3+/ ions. The rate-equations model includes uniform upconversion mechanisms from /sup 4/I/sub 13/2/ and /sup 4/I/sub 11/2/ erbium levels and an Yb/sup 3+/ to Er/sup 3+/ pair-induced energy transfer process. Numerical results demonstrate the possibility of fabricating short- and high-gain integrated optical amplifiers; it is shown that net gain as high as 3 dB/cm can be obtained. >
TL;DR: In this paper, a theoretical model is presented to evaluate performances of frequencies converters based on highly nondegenerate four-wave mixing (FWM) in semiconductor amplifiers.
Abstract: All optical frequency converters are key devices for new-conception optical networks A theoretical model is presented to evaluate performances of frequencies converters based on highly nondegenerate four-wave mixing (FWM) in semiconductor amplifiers Conversion efficiency and noise performances are evaluated in generic saturation conditions and compared with experimental results >
TL;DR: In this article, the authors used a statistical model of user access in a wireless network and showed that by accepting a modest ( > 0.5 GHz) link, a user can receive an antenna remoting signal from analog fiber-optic link.
Abstract: Analog fiber-optic links can be used for antenna remoting in microcellular networks. Using a statistical model of user access in a wireless network, it is shown that by accepting a modest ( >
TL;DR: In this paper, a vertical grating assisted codirectional coupler laser with a super structure grating distributed Bragg reflector was demonstrated with a record stepwise tuning range of 114 nm with good side-mode suppression.
Abstract: ―A vertical grating assisted codirectional coupler laser with a super structure grating distributed Bragg reflector is demonstrated. A record stepwise tuning range of 114 nm was measured with good side-mode suppression. The tuning behavior of the device is investigated showing a potential of a tuning range exceeding 100 nm with complete wavelength coverage.
TL;DR: In this paper, the stimulated Raman scattering crosstalk in intensity-modulated WDM systems is analyzed, including modulation statistics, and the actual penalty is found to be lower than that expected from a worst-case analysis.
Abstract: Stimulated Raman scattering crosstalk in intensity-modulated WDM systems is analyzed, including modulation statistics. The actual penalty is found to be lower than that expected from a worst-case analysis. For a large number of channels, the depletion due to stimulated Raman scattering becomes half of the value found with a worst-case analysis and assumes a deterministic behavior. >
TL;DR: In this article, a batch-assembled optoelectronic packaging technology based on silicon surface-micromachined alignment mirrors is described, which has the functionality, stability and accuracy required for active semiconductor laser-to-filter (single mode) coupling.
Abstract: We describe a batch-assembled optoelectronic packaging technology based on silicon surface-micromachined alignment mirrors and demonstrate that these mechanical structures have the functionality, stability and accuracy required for active semiconductor laser-to-filter (single mode) coupling. In initial experiments, we measure an open-loop position accuracy of 0.2 /spl mu/m, and we achieve repeatable 45% coupling efficiency with good mechanical stability. >
TL;DR: In this article, the authors present a simple and efficient technique to produce double sideband suppressed carrier (DSBSC) modulation for coherent analog optical communications, where at the appropriate bias point the carrier exits one of the output ports while the information carrying sidebands exit the other output port.
Abstract: We present a simple and efficient technique to produce double sideband suppressed carrier (DSBSC) modulation for coherent analog optical communications. When operating a Mach-Zehnder electro-optic modulator at the appropriate bias point the carrier exits one of the output ports while the information carrying sidebands exit the other output port. The absence of a strong carrier component in the DSBSC output allows the use of an optical amplifier immediately following the modulator where the light signals are still relatively strong hence preserving the high S/N. In our experiments using heterodyne detection at 1319 nm, we show a -28-dB carrier suppression using a commercial M-Z modulator. >
TL;DR: In this paper, a liquid-crystal and grating-based optical cross-connect add-drop switch that operates simultaneously on several wavelengths channels was proposed and demonstrated, with 4 nm channel spacing, a flat-top frequency response and 30 dB extinction ratio.
Abstract: We propose and demonstrate a liquid-crystal and grating based optical cross-connect add-drop switch that operates simultaneously on several wavelengths channels. We demonstrate an 8 channels switch with 4 nm channel spacing, a flat-top frequency response and 30 dB extinction ratio. >
TL;DR: In this paper, a single-mode distributed feedback (DFB) laser diodes were constructed from a single epitaxial growth using lateral evanescent coupling of the optical field to a surface grating etched along the sides of the ridge.
Abstract: Single-mode distributed feedback (DFB) laser diodes typically require a two-step epitaxial growth or use of a corrugated substrate. We demonstrate InGaAs-GaAs-AlGaAs DFB lasers fabricated from a single epitaxial growth using lateral evanescent coupling of the optical field to a surface grating etched along the sides of the ridge. A CW threshold current of 25 mA and external quantum efficiency of 0.48 mW/mA per facet were measured for a 1 mm cavity length device with anti-reflection coated facets. Single-mode output powers as high as 11 mW per facet at 935 nm wavelength were attained. A coupling coefficient of at least 5.8 cm/sup -1/ was calculated from the subthreshold spectrum taking into account the 2% residual facet reflectivity. >
TL;DR: A novel add/drop optical filter providing arbitrary channel arrangements between two input wavelength division multiplexing (WDM) signals and two output WDM signals is presented.
Abstract: A novel add/drop optical filter providing arbitrary channel arrangements between two input wavelength division multiplexing (WDM) signals and two output WDM signals is presented. This device can have useful applications in WDM optical communication systems. >
TL;DR: In this paper, an anamorphic fiber microlens is evaluated for coupling between laser diodes and single-mode fibers, based on scalar diffraction and Gaussian mode shapes for the laser and fiber fields, and the average coupling efficiency of this lens is measured to be 78%.
Abstract: An anamorphic fiber microlens is evaluated for coupling between laser diodes and single-mode fibers. A theoretical model, based on scalar diffraction and Gaussian mode shapes for the laser and fiber fields, is developed to predict the coupling performance of this microlens. Experimentally, the average coupling efficiency of this lens is measured to be 78%. The lateral sensitivity is also measured and compared with the values predicted by the model. >
TL;DR: In this article, a silicon Fabry-Perot waveguide modulator, operating at the fiber optic communication wavelengths of 1.3 and 1.55 /spl mu/m, has been entirely fabricated using microelectronic techniques.
Abstract: A silicon Fabry-Perot waveguide modulator, operating at the fiber optic communication wavelengths of 1.3 and 1.55 /spl mu/m, has been entirely fabricated using microelectronic techniques. The planar optical cavity has been defined by plasma etching and has a length of 100 /spl mu/m. The device, based on the thermooptic effect, is electrically driven and exhibits a maximum modulation depths of 60%. The measured -3 dB bandwidth is 700 kHz, which is by far the best result ever reported, to our knowledge, for thermooptic effect based modulators. >