Ga0.35In0.65 N0.02As0.08/GaAs bidirectional light-emitting and light-absorbing heterojunction operating at 1.3 μm

The Top-Hat hot electron light emission and lasing in semiconductor heterostructure (HELLISH)-vertical-cavity semiconductor optical amplifier (THH-VCSOA) is a bidirectional light-emitting and light-absorbing heterojunction device. The device contains 11 Ga0.35In0.65 N0.02As0.08/GaAs MQWs in its intrinsic active region which is enclosed between six pairs of AlAs/GaAs top distributed Bragg reflectors (DBRs) and 20.5 pairs of AlAs/GaAs bottom DBR mirrors. The THH-VCSOA is fabricated using a four-contact configuration. The wavelength conversion with amplification is achieved by the appropriate biasing of the absorption and emission regions within the device. Absorption and emission regions may be reversed by changing the polarity of the applied voltage. Emission wavelength is about 1,300 nm and a maximum gain at this wavelength is around 5 dB at T = 300 K

Gain studies of 1.3-μm dilute nitride HELLISH-VCSOA for optical communications

The hot electron light emitting and lasing in semiconductor heterostructure-vertical-cavity semiconductor optical amplifier (HELLISH-VCSOA) device is based on Ga0.35In0.65 N0.02As0.08/GaAs material for operation in the 1.3-μm window of the optical communications. The device has undoped distributed Bragg reflectors (DBRs). Therefore, problems such as those associated with refractive index contrast and current injection, which are common with doped DBRs in conventional VCSOAs, are avoided. The gain versus applied electric field curves are measured at different wavelengths using a tunable laser as the source signal. The highest gain is obtained for the 1.3-μm wavelength when an electric field in excess of 2 kV/cm is applied along the layers of the device

Optical gain in 1.3-μm electrically driven dilute nitride VCSOAs

We report the observation of room-temperature optical gain at 1.3 μm in electrically driven dilute nitride vertical cavity semiconductor optical amplifiers. The gain is calculated with respect to injected power for samples with and without a confinement aperture. At lower injected powers, a gain of almost 10 dB is observed in both samples. At injection powers over 5 nW, the gain is observed to decrease. For nearly all investigated power levels, the sample with confinement aperture gives slightly higher gain

Electrical characterisation of p-doped distributed Bragg reflectors in electrically pumped GaInNAs VCSOAs for 1.3μm operation

The high resistivity that is encountered in p-type DBRs is an important problem in vertical cavity surface emitting lasers and optical amplifiers (VCSELs and VCSOAs). This is because the formation of potential barriers at the interfaces between layers of high and low refractive index inhibits the carrier flow, thus increasing the DBR series resistance. In this work, the electrical characteristics of two p-type doped DBR structures grown on undoped and p-type doped GaAs substrates have been investigated. The DBRs are designed for VCSOAs operating at 1.3 mu m and consist of 14-periods of alternating GaAs and Al0.9Ga0.1As in the first sample and 14-periods of GaAs and Al0.3Ga0.3As/Al0.9Ga0.1 As in the second one. For the longitudinal transport sample. Hall mobility and sheet carrier density were measured in the temperature range from 77 to 300 K. In the vertical transport sample, current-voltage (l-V) measurements across the DBR layers were carried out at different temperatures in the range between 15 and 300K. We achieved resistivity reduction in our samples by using an interface composition grading technique aimed at improving the VCSOA characteristics