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For chip-scale interconnection, 4 times 12 vertical-cavity surface-emitting laser (VCSEL) arrays have been optimized. Each flip-chip bondable bottom-emitting oxide-confined 985 nm VCSEL have integrated backside lenses, and is capable of modulation at >20 Gb/s with a low current density of only 9.9 kA/cm2. An aggregate data rate of 960 Gb/s was obtained from a chip area of only 1.4 mm times 3.75 mm, or 18.3 Tb/(sldrcm2).

Folded-cavity (FC) resonators, which are based on shallow-etched ridge waveguides combined with four deeply etched turning mirrors, are designed and fabricated. The device consists of a resonant FC and a bus waveguide coupled to it through a directional coupler. Optical passive filters, based on this technology, exhibit quality factors in the excess of 5000, with a low insertion loss of 5 dB (including the input coupling loss to a fiber) and more than 15-dB extinction at resonance. When the filter is combined with an electroabsorption active region and is designed to operate in the overcoupled regime, a low-voltage/high-extinction-ratio resonant modulation becomes feasible. The resonant modulator exhibits a low insertion loss (greater than 22-dB extinction at resonance) and offers a low-voltage operation. A change in the applied voltage by 0.7 V (close to the critically coupled conditions) leads to a transmission change of more than 16 dB. Open eye diagrams at 12 Gb/s are presented. To decrease the insertion loss, multiple material bangaps are further monolithically integrated across the wafer by utilizing the quantum-well-intermixing techniques

For pt. I see ibid., vol. 44, no. 3, p. 652-7 (1997). The method for analyzing surface transverse wave (STW) devices by using a coupling-of-modes (COM) formalism has been completed, covering the STW electromechanical coupling coefficient (ECC). An ECC analytical formula has been derived by fitting numerical results from STW effective permittivity analysis. The ECC exhibits frequency and mass-loading variation. Using this new result, a satisfactory agreement with available experimental frequency characteristics of STW two-port quartz resonators has been achieved, without the necessity of additional experimental information. In its present form, the method is self-consistent and applicable to arbitrary STW layouts.

In this letter, we demonstrate error-free operation of a 12-fiber /spl times/4-wavelength /spl times/5.21-Gb/s parallel-wavelength-division-multiplexed (PWDM) optical link. The 250-Gb/s transmitter and receiver assemblies each have a 5/spl times/8-mm footprint and consume a combined power of 1.5 W. To our knowledge, this is the first publication of a fully functional PWDM optical interconnect as well as the highest demonstrated bandwidth per unit area and bandwidth per unit power consumption for any multiple-channel fiber-optic interconnect. This technology is intended for short-distance high-bandwidth-density applications such as multiprocessor computer backplanes.

The direct integration of dense 48-channel parallel multiwavelength optical transmitter and receiver subassemblies directly onto a first level package using a flex lead attach has been demonstrated. Such an approach, at 10 Gb/s/channel would provide a linear edge bandwidth density of 300 Gb/s/cm. By attaching dense multichannel optical subassemblies directly onto an MCM, the performance limitations of the connectors and node card wiring can be avoided and the total bandwidth off the MCM can be increased while also enabling longer distance and higher speed signaling. This approach involves only a modest modification to the bent-flex approach commonly used for parallel optical modules intended for board mounting but enables a significant density and performance improvement for this application.

We have demonstrated high density, 2D (4x12) VCSEL ar rays operating at an aggregate data rate of over 480Gb/s in an aerial density of 1400x3750 µ m 2 , or 9.14 Tbs/cm 2 . These flip-chip, bottom-emitting 990nm VCSELs have low drive voltage, low electrical parasitics, improved thermal impedance and 2D scalability over their wire-bonded top emitting counterparts. Excellent high speed performance was obtained through the use of 1) compressively strained InGaAs MQW active region 2) low parasitic capacitance oxide-confined VCSEL structures and 3) low series resistance, high index contrast AlGaAs/GaAs mirrors. 10Gb/s operation was obtain ed with low operating current density of ~6kA/cm 2 at 70 o C. Our best results to date have achieved data rates greater than 15Gb/s @70 C at a current density less than 10kA/cm 2 . The device results show good agreement with theoretically calculated/simulated values. 1. INTRODUCTION Future rack-to-rack and board-to-board computer interconnects will require data rates in excess of 20Gb/s while maintaining the smallest aerial density and low power consumption. 990nm VCSELs exhibit better high speed performance, improved thermal behavior an d the advantage of flip-chip 2D arrays over their 850nm counterparts. 990nm VCSELs have improved carrier confinement resulting from a higher conduction band offset, improved differential gain and lower transparency due to strain [1] and low optical attenuation through the GaAs substrate. The use of higher contrast (compared to 850nm) AlGaAs DBRs improves the mode volume and thermal resistan ce of these devices. The use of AlGaAs DBRs on GaAs substrates in these VCSELs allows robust epi and device process window and lends itself to manufacturability. 2. METHODOLOGY Epitaxial growths were performed by low pressure metalorganic chemical vapor deposition (MOCVD), in a production scale reactor with arsine, trimethyl- group III alkyl precursors, and disilane (0.01% in H

A low-voltage folded cavity resonant modulator, based on shallow-etched ridge waveguides combined with four deeply etched turning mirrors is demonstrated. The resonant modulator exhibit a high quality factor in the excess of 5000, low insertion loss, greater than 22 dB extinction at resonance and offers low-voltage operation. A change in the applied voltage by 0.7 V leads to transmission change of more than 16 dB. The DC performance of the modulator is presented

This article presents a promising approach for multi-Tb/s optical interconnects. This approach is contained in the MAUI project, which develops a parallel multiwavelength optical subassembly (PMOSA) that uses PWDM to gain the component-density advantages of two-dimensional parallel optics and the connector and cabling density advantages of CWDM. In the MAUI approach, a standard multimode 12-fiber ribbon is used with 4 wavelengths transmitted through each fiber, for a total of 48 optical channels.

This paper describes a 3 W 500-Gbps (4x12x10.42-Gb/s) parallel wavelength-division multiplexed optical interconnect that uses a 12-fiber ribbon with 4 wavelengths per fiber. The transmitter and receiver are each 5mm x 8 mm chip-scale packages.

This paper describes a 500-Gbps parallel wavelength-division multiplexed (PWDM) optical interconnect where 48 channels of 10.42-Gbps data are transmitted over a parallel 12-fiber ribbon with 4 wavelengths per fiber. The transmitter and receiver are each chip-scale packages with a footprint of 5 mm times 8 mm and a combined power consumption of 3 W. This work is motivated by the continually increasing bandwidth needs of short-distance computer processor interconnects, which are demanding optical solutions that maximize bandwidth per unit area, power consumption, and cost

We discuss a 12-fiber /spl times/ 4-wavelength /spl times/ 10.4-Gbit/s short-distance parallel-wavelength-division-multiplexed optical interconnect. The 0.5-Tbit/s transmitter and receiver assemblies each have a 5 /spl times/ 8-mm footprint and together consume 2.95 W.

This work presents the first fully-functional 48-channel parallel-wavelength-division-multiplexed (PWDM) transmitter, receiver and link results at a per-channel data rate of 5.21-Gb/s. This high-density PWDM optical interconnect gives an aggregate link bandwidth of a quarter terabit per second.

Blotekjaer's theory, extended by Hashimoto and coworkers, for analyzing surface transverse waves has been modified in the part concerning the effect of finite electrode thickness. First order Datta-Hunsinger's surface boundary conditions have been introduced in the effective permittivity of the substrate, to account for the mechanical loading. The dispersion STW velocity curves have been obtained over the entire frequency stopband, including the interval where intensive excitation of bulk modes occurs. The effective permittivity also allows obtaining the electromechanical coupling of the grating mode. Its numerical analysis reveals a strong dependence on the metalization ratio and mass-loading, in close agreement with results from Hasimoto's discrete Green function theory.

The dispersion characteristics of surface transverse waves (STWs) on 36/spl deg/ Y cut quartz substrate have been analysed numerically. A closed-form dispersion relation has been introduced in the equations of the coupling-of-modes (COM) theory to account for the variation of trapping with frequency. The transmission and reflection coefficients at the finger edges have been determined from the stopband characteristics. Introducing an electromechanical coupling which varies with the electrode mass loading, quantitative agreement with experimental results on 650 MHz two-port STW resonators has been achieved.

A novel packaging concept is demonstrated where parallel-optical subassemblies are mounted on the same substrate as processor chips for processor-to-processor communication within a high-end server. A single-channel bit-error ratio