K.A. Black

Superlattice barrier 1528-nm vertical-cavity laser with 85/spl deg/C continuous-wave operation

We report 85 C continuous wave operation of a 1528 nm VCSEL with an InP-InGaAsP active region and wafer fused GaAs-AlGaAs mirrors. A superlattice barrier was used to reduce defect density in the wafer fused active region.

Long wavelength vertical-cavity semiconductor optical amplifiers

This paper overviews the properties and possible applications of long wavelength vertical-cavity semiconductor optical amplifiers (VCSOAs). A VCSOA operating in the 1.3-/spl mu/m wavelength region is presented. The device was fabricated using wafer bonding; it was optically pumped and operated in reflection mode. The reflectivity of the VCSOA top mirror was varied in the characterization of the device. Results are presented for 13 and 12 top mirror periods. By reducing the top mirror reflectivity, the amplifier gain, optical bandwidth, and saturation output power were simultaneously improved. For the case of 12 top mirror periods, rye demonstrate 13-dB fiber-to-fiber gain, 0.6 nm (100 GHz) optical bandwidth, a saturation output power of -3.5 dBm and a noise figure of 8.3 dB. The switching properties of the VCSOA are also briefly investigated. By modulating the pump laser, we have obtained a 46-dB extinction ratio in the output power, with the maximum output power corresponding to 7-dB fiber-to-fiber gain. All results are for continuous wave operation at room temperature.

Improved luminescence from InGaAsP/InP MQW active regions using a wafer fused superlattice barrier

This paper investigates the luminescence properties of InP/InGaAsP multiple quantum well (MQW) laser active regions. Room temperature photoluminescence studies were performed on doped and undoped active regions before fusion, after fusion, after thermal cycling, and after rapid thermal annealing. It is shown that quantum well luminescence intensity degrades considerably after wafer fusion. The introduction of a superlattice defect blocking layer at the fusing surface of the MQW active region not only prevents degradation of the luminescence, but actually improves the luminescence of the MQW active region through the fusion process by a factor of four.

Long wavelength vertical cavity lasers

The need for low cost, high speed telecommunication sources demands the maturation of long wavelength vertical cavity lasers (VCLs). Both long haul fiber optic systems and gigabit ethernet links are potential markets for 1.3 and 1.55 micron VCLs. This past year has seen much progress to this end, but the emerging technology has yet to be determined. This paper overviews critical issues in long wavelength VCL design, and discusses the most recent technological advances in the field.

Small-signal frequency response of long-wavelength vertical-cavity lasers

The small-signal frequency response of long-wavelength vertical-cavity lasers (LW-VCLs) is of interest in determining the ultimate bandwidth of these devices for use in terrestrial networks. This letter analyses two distinct device structures of double wafer-bonded vertical-cavity lasers operating at 1.5 /spl mu/m and compares their high-speed performance. We demonstrate the highest modulation bandwidth and the highest modulation current efficiency of an electrically pumped LW-VCL of 7 and 4.1 GHz//spl radic/mA, respectively.

Harmonic distortion in 1.55-μm vertical-cavity lasers

We investigate second and third order harmonics in the analog modulation response of InP-GaAs fused 1.55-/spl mu/m vertical-cavity lasers (VCLs). These devices exhibit the lowest threshold current as well as the highest temperature of continuous-wave operation of any electrically pumped long wavelength VCL. Near the resonance frequency, harmonic distortion is dominated by electron-photon interaction, and it is close to the distortion measured with in-plane lasers. At low frequencies, distortions seem to be dominated by carrier transport effects. At 1 GHz modulation frequency, we measure a maximum spur-free dynamic range of 64 dB Hz/sup 1/2/ for second-order harmonic distortion and 81-dB Hz/sup 2/3/ for third-order harmonic distortion.

Superlattice barrier 1528 nm vertical cavity laser with 85/spl deg/C continuous wave operation

We report 85/spl deg/C continuous-wave electrically pumped operation of a 1528-nm vertical-cavity laser. An InP-InGaAsP active region was wafer bonded to the GaAs-AlGaAs mirrors, with a superlattice barrier to reduce the defect density in the active region.

Fusion bonding : hetero-interfacial materials analysis and device application

A large number of novel devices have been recently demonstrated using wafer fusion to integrate materials with different lattice constants. In many cases, devices created using this technique have shown dramatic improvements over those which maintain a single lattice constant. We present device results and characterizations of the fused interface between several groups of materials.