[Show abstract][Hide abstract] ABSTRACT: Ridge waveguide distributed feedback (DFB) lasers emitting at 1.3
μm wavelength have been fabricated by one-step metal-organic chemical
deposition over a first order grating in an InP substrate. Threshold
currents as low as 13-18 mA were obtained for devices with as-cleaved
facets and 15-20 mA for devices with one AR-coated facet. A slope
efficiency as high as 0.32 mW/mA, single mode performance up to 20 mW,
and a side mode suppression ratio of 45 dB have been achieved. For
lasers with a coupling×length product, κL, of 2.5-3.5 and
the single longitudinal-mode detuned 10-20 nm to the shorter wavelength
side of the material gain peak, a high resonance frequency and a small
wavelength chirp have been observed. Small signal frequency responses
were measured with a -3 dB bandwidth of 11 GHz at 12 mW output power.
The devices showed good open eye patterns under direct modulation up to
No preview · Article · Nov 1994 · IEE Proceedings - Optoelectronics
[Show abstract][Hide abstract] ABSTRACT: Avalanche photodiodes (APDs) are required for long distance fiber optical systems at wavelengths of 1.3 and 1.55 micrometers . Presently deployed systems operate at speeds up to 2.4 Gb/s, with increasing volumes. It is becoming increasingly necessary to produce low-cost, high-performance planar APDs. Most commercial InP/InGaAs APDs employ a separate absorption, grading, and multiplication (SAGM) design. However, this approach has severe process limitations for obtaining functioning APDs. Greater growth and processing flexibility is obtained from the separate absorption, grading, charge and multiplication (SAGCM) APD. In this work the influence of the layer thicknesses, junction depth and doping on the performance of SAGCM APDs is described both theoretically and experimentally. Theoretically, an analytical model of the (delta) -doped (ideal SAGCM) APD is presented, both neglecting and taking into account ionization in the InGaAs. In addition to the performance predictions with respect to fabrication parameters, this model also predicts that the gain depends on the wavelength of light (e.g. 1.3 or 1.55 micrometers ). Experimentally, whole 2-inch wafer performance results are interpreted with respect to variations in growth and processing parameters. The results are in good agreement with the predictions of the model.
No preview · Article · May 1994 · Proceedings of SPIE - The International Society for Optical Engineering
[Show abstract][Hide abstract] ABSTRACT: The factors affecting the quality of regrowth of semi-insulating λ = 1.1 μm InGaAsP around circular mesas for the fabrication of circular grating distributed-Bragg-reflector surface-emitting lasers were investigated. Reactive ion etching of the mesas avoids the exposure of no growth planes on the mesa sidewalls, which results in good regrowth morphology around the entire mesa at a growth pressure of 50 mbar. High resolution scanning photoluminescence of the regrown quaternary material reveals a minimal 4 nm wavelength shift to longer wavelengths as the mesa edge is approached. A map of the photoluminescence intensity indicates that the quality of the regrown material is uniform around the periphery of the mesas. Fe doping of λ = 1.1 μm InGaAsP increases linearly with reactor gas pressure for fixed dopant and total gas flows, so the dopant flow must be adjusted for regrowth at a different reactor pressure if the same doping is desired. Activation of Fe in λ = 1.1 μm InGaAsP is independent of hydride concentration in the reactor in the range of (2–9)x10-5 mol/l, and is virtually complete.
No preview · Article · Nov 1993 · Journal of Crystal Growth
[Show abstract][Hide abstract] ABSTRACT: A method for producing durable fused silica self‐interference grating photomasks is described. These masks allow repeated printing of both uniform and phase adjusted gratings. Periods as fine as 200 nm have been demonstrated. The fabrication of these masks via holographic and focused ion beam lithography and their use as a lithography tool are explained. Distributed feedback lasers, with gratings made by this technique, were produced. These lasers operated in a single longitudinal mode at a wavelength of either 1.55 or 1.3 μm.
No preview · Article · Feb 1993 · Applied Physics Letters
[Show abstract][Hide abstract] ABSTRACT: The design, fabrication, and lasing characteristics of electrically pumped circular-grating distributed-Bragg-reflector (CG-DBR) surface-emitting lasers, were studied. Surface-emitted lasing action was achieved at room temperature under pulsed condition. Although the measured threshold current is still higher than theoretical calculations, CW operation should be possible by improving the fabrication and the device structure.< >
No preview · Article · Oct 1992 · IEEE Photonics Technology Letters
[Show abstract][Hide abstract] ABSTRACT: The first 1.3 mu m electrically-pumped surface-emitting circular grating DBR laser operating at room temperature in a GaInAsP/InP heterostructure is reported. The threshold current was 170 mA. The surface-emitted output power was 10 mW.
No preview · Article · Jun 1992 · Electronics Letters
[Show abstract][Hide abstract] ABSTRACT: The lasing action in surface-emitting DFB lasers with circular grating (SE-CG DFB) is reported for the first time. 1.283 mu m laser oscillation is demonstrated by optical pumping. The threshold pumping power density is estimated to be 16.2 kW/cm<sup>2</sup>. The pulsed output power is more than 25 mW.
No preview · Article · Oct 1991 · Electronics Letters
[Show abstract][Hide abstract] ABSTRACT: A fully functioning optoelectronic integrated circuit, a
transmitter comprising an AlGaAs GRINSCH (graded-index separate
confinement heterostructure) laser diode (LD), a back facet monitor
diode, and a driving circuit made up of four MESFETs, has been
successfully fabricated. The flexibility that can be attained with
facets completely fabricated by reactive ion etching (RIE) is
demonstrated on mutually perpendicular stripe lasers side-by-side on the
same wafer. The circuits were made on semi-insulating GaAs wafers using
two separate MBE (molecular-beam epitaxy) growth runs for the MESFETs
and the laser diodes, respectively. More than 50% of the integrated
circuits on the 3" wafer were fully functional, although some variation
of the FET threshold voltage, transconductance, and the gain-guided LD
threshold current was observed. Typical values were -1.5 V, 98 mS/mm,
and 100 mA, respectively. Measured speeds of operation exceeded 1 Gb/s