Multiple-wavelength Vertical-cavity Laser Arrays Research Articles

Postgrowth tuning of semiconductor vertical cavities for multiple-wavelength laser arrays

Combined lateral-vertical oxidation of AlGaAs is investigated as a means of tuning the resonant wavelength of a semiconductor microcavity after the epitaxial growth. It is shown that this technique can provide arrays with a wavelength spread equal to the cavity's free spectral range with a single postgrowth processing step. Design issues for multiple-wavelength vertical-cavity laser arrays using this postgrowth tuning technique are discussed, comparing the performance of devices with all-semiconductor and partially or totally oxidized Bragg mirrors. Experimental results are presented on arrays with a 48-nm lasing span around 970 nm, using partially and totally oxidized mirrors.

Multiple-wavelength vertical-cavity laser arrays based on postgrowth lateral-vertical oxidation of AlGaAs

We demonstrate that combined lateral-vertical oxidation of AlGaAs can be used to change the resonant wavelength of an optical cavity after the single epitaxial growth. A multiple-wavelength array of vertical-cavity surface-emitting lasers with a 48 nm wavelength span has been realized using this technique.

Multimode WDM optical data links with monolithically integrated multiple-channel VCSEL and photodetector arrays

We report on the design and implementation of a novel multiple-wavelength optical data link for low-cost multimode wavelength-division multiplexing (WDM) local-area network applications. This link utilizes a monolithically integrated multiple-wavelength vertical-cavity laser array and a narrow-band resonant-cavity photodetector array to transmit multiple channels of information simultaneously via a single multimode fiber. A detailed analysis on wavelength tuning and threshold characteristics of different laser cavity designs is presented. Theoretical results are compared to our experimental data. On the receiver part, both Schottky and p-i-n photodetectors with a single- or coupled-cavity structure are discussed. A novel p-i-n resonant-cavity photodetector design with a partially oxidized front mirror for linewidth control is proposed. Moreover, we also demonstrate preliminary measurements on the optical link built with our multiple-wavelength vertical-cavity laser array and photodetector array. Finally, the feasibility of constructing a multiwavelength optical data link with a single dual-core multimode fiber and an integrated laser/detector array is evaluated.

Optical crosstalk in monolithically-integrated multiple-wavelength vertical-cavity laser arrays for multimode WDM local-area networks

The optical crosstalk between lasers in densely-packed multiple-wavelength vertical-cavity photonic integrated emitter arrays is studied for multimode wavelength-division multiplexing applications. It is found that a significant number of photocarriers are generated by spontaneous emission of an adjacent laser. However, an appropriate prebiasing scheme or device design can reduce the crosstalk to < –20 dB.

Low-threshold multiple-wavelength vertical-cavity laser arrays obtained by postgrowth wet oxidation

A mask-defined array of multiple-wavelength verfical-cavity surface-emitting lasers with submilliamp threshold currents over a 22 nm wavelength span has been fabricated with a single epitaxial growth on a conventional substrate. Tuning is achieved by using the combination of lateral and vertical wet oxidation of an AlGaAs layer inside the cavity.

Multiple-wavelength Vertical Cavity Laser Arrays with Wide Wavelength Span and High Uniformity

Multiple-wavelength Vertical Cavity Laser Arrays with Wide Wavelength Span and High Uniformity

Location-resolvable optical monitored growth of multiple-wavelength vertical-cavity laser arrays

Multiple-wavelength vertical-cavity surface-emitting laser (VCSEL) arrays are fabricated using a location-resolvable in situ optical calibration method and a patterned-substrate growth technique in a molecular beam epitaxy (MBE) system. The high and low wavelength limits are achieved within 0.28% accuracy and with a 2.66 A wavelength standard deviation from 4 × 35 arrays.

Multiple-wavelength vertical cavity laser arrays on patterned substrates

We demonstrate a spatially chirped resonant wavelength in vertical cavities and vertical cavity surface emitting lasers (VCSEL's) grown by Molecular Beam Epitaxy. The wavelength shift is achieved by varying the GaAs growth rate across the wafer using a patterned backing substrate to induce a lateral temperature profile. Temperature patterns transfer to thickness patterns with a resolution on the millimeter scale. We demonstrate 8-nm periodic cavity mode shifts in GaAs-AlAs Fabry-Perot vertical cavities, and a 20-nm shift in lasing wavelength in a VCSEL array. >