Xiaojie Wang

Self-aligned current aperture in native oxidized AlInAs buried heterostructure InGaAsP/InP distributed feedback laser

A InGaAsP/InP self-aligned, native oxidized buried heterostructure (BH) distributed feedback (DFB) laser is proposed. It is as easy to process as the ridge waveguide DFB laser and has superior performance. The current aperture can be easily controlled without selective regrowth. The laser exhibits a low threshold of 5.0 mA with 36 dB side mode suppression ratio at the emission wavelength of 1.562 mu m. It emits in a single lobe with full width at half maximum angles of 33.6 degrees and 42.6 degrees for the lateral and vertical fields, respectively. Its beam is more circular than that of the as-grown BH laser because the lower refractive index of oxide compared to the as-grown layer and results in a larger lateral optical confinement. Its characteristic temperature (T-0) is 50 K at room temperature but increases in value at the higher temperature range

High power picosecond pulse generation from a two-section InGaAsP-InP MQW complex-coupled DFB laser diode

We show that high power picosecond pulses can be generated from a InGaAsP compressively strained two-section MQW laser diode by setting an optimal amplitude and time delay between the electrical pulses applied to each section of the device.

Wavelength tunable electroabsorption modulated DFB laser with thin film heater

A light source capable of wide-band wavelength tuning is essential to realize more flexible and efficient optical networks in WDM transmission systems. Although tunable electro-absorption (EA) modulated DFB lasers (T-EML) with bent waveguide and tunable DBR lasers integrated with a EA modulator (MD) have been successfully fabricated, the most practical light sources are tuned to the desired WDM channel frequency by the thermal effect. We propose and fabricate a single ridge waveguide T-EML with a thin film heater (TF-H) along the laser ridge by two-step MOVPE including selective area growth.

A novel 1.3-mu m high T-0 AlGaInAs/InP strained-compensated multi-quantum well complex-coupled distributed feedback laser diode

A 1.3-µm AlGaInAs/InP buried heterostructure (BH) stripe distributed feedback laser with a novel AlInAs/InP complex-coupled grating grown by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) is proposed and demonstrated. A high characteristic temperature (T0=90 K between 20–80°C) and temperature-insensitive slope efficiency (0.25 dB drop from 20 to 80°C) in 1.3 µm AlGaInAs/InP DFB lasers was obtained by introducing Al(Ga)InAs graded-index separate-confinement heterostructure (GRINSCH) layers and a strained-compensated (SC) multi-quantum well (MQW).

Self-aligned AlInAs native oxidized buried hetero-structure InGaAsP/InP distributed feedback laser with circular beam and high T/sub 0/ potential

InGaAsP/InP self-aligned native oxidized buried heterostructure distributed feedback (SA-NOBH-DFB) laser is proposed. It is easy to process as ridge waveguide DFB laser and has a superior performance. The current aperture can be easily controlled without selective regrowth. Preliminarily, the laser exhibited a low threshold of 5.0 mA with 36 dB side mode suppression ratio (SMSR) at 1.562 /spl mu/m. It shows a single transverse mode with full width at half maximum angles of 33.6/spl deg/ and 42.6/spl deg/ for the lateral and vertical fields, respectively. Its beam is move circular than that of the as-grown BH laser because the refractive index of oxide is lower than as-grown layer and results in larger lateral optical confinement. Its characteristic temperature (T/sub 0/) is 50 K in average but it even becomes higher in high temperature region.

Single ridge waveguide electroabsorption modulated DFB laser for 2.5Gb/s transmission

In this paper we proposed a single ridge waveguide electroabsorption modulated distributed feedback laser (EML) for long-haul high-speed optical fiber communication system. This EML was successfully fabricated by two step metal organic vapor phase epitaxy (MOVPE) including selective area growth (SAG) and helium partially implantation. No obvious changes of the threshold current (< 0.2 mA), extinction ratio (< 0.1 dB), output power (< 0.2 dBm) and isolation resistance were achieved in the preliminary aging test. With 2.5 Gb/s NRZ modulation, no power penalty was observed after the optical signal was transmitted through 280 Km normal single mode fiber.

A novel passivated Al(In)As/InP current blocking grating for 1.3 /spl mu/m AlGaInAs/InP complex-coupled DFB laser fabrication

For improvements of the temperature characteristics of AlGaInAs/InP MQW-SCH DFB lasers for uncooled light source application, we proposed and demonstrated experimentally a new CB grating which can be fabricated through a passivated AlInAs current blocking region. The CW operation at room temperature of the 1.3 /spl mu/m AlGaInAs/InP complex-coupled DFB laser was realized.

High T/sub 0/ 1.3 /spl mu/m AlGaInAs/InP distributed feedback laser with complex-coupled grating growth by LP-MOCVD

A high T/sub 0/ 1.3 /spl mu/m AlGaInAs-InP MQW DFB laser, which was grown by LP-MOCVD, is demonstrated for the first time. The T/sub 0/ is up to 98K and the drop of 0.5dB in slope efficiency is achieved within 20 C to 80 C. A DFB laser with current blocking grating was realized successfully.

Growth factor of Fe-doped semi-insulating InP by LP-MOCVD

The semi-insulating InP has been grown using ferrocene as a dopant source by low pressure MOCVD. Fe doped semi-insulating InP material whose resistivity is equal to 2.0 X 108(Omega) *cm and the breakdown field is greater than 4.0 X 104Vcm-1 has been achieved. It is found that the magnitude of resistivity increases with growing pressure enhancement under keeping TMIn, PH3, ferrocene [Fe(C5H5)2] flow constant at 620 degrees Celsius growth temperature. Moreover, the experimental results which resistivity varies with ferrocene mole fraction are given. It is estimated that active Fe doping efficiency, (eta) , is equal to 8.7 X 10-4 at 20 mbar growth pressure and 620 degrees Celsius growth temperature by the comparison of calculated and experimental results.

1.3-μm InGaAsP/InP strained-layer multiquantum well complex-coupled distributed feedback laser

1.3 micrometers strained-layer multi-quantum wells complex-coupled distributed feedback lasers with a wide temperature range of 20 to 100 degree(s)C are reported. The low threshold current of 10 mA and high single-facet slope efficiency of 0.3 mW/mA were obtained for an as cleaved device. The single mode yield was as high as 80%.