Stable CW operation of a MQW laser emitting at 1.54 μm on a Sisubstrate at room temperature

Summary form only given. The MQW laser exhibits no degradation during 500 h of CW operation. Employing a hybrid organometallic vapor-phase epitaxy/vapor-phase epitaxy method, high-quality InP films with a full width at half maximum for the X-ray rocking curve of 110 arcsec, a dislocation density of 10⁷ cm^-2, and low residual stress of 2×10⁸ dyn/cm² were obtained. Results of a preliminary CW aging test at room temperature showed no operational degradation over 500 h with a constant output power of 2 mW per facet. This LD appears to be a promising light source candidate for application to OEICs (optoelectronic integrated circuits)     

Very large bandwidth strained MQW DFB laser at 1.3 μm

A 3-dB bandwidth of 20 GHz has been demonstrated for a compressively strained multiquantum well InGaAsP-InP DPB laser operating at 1.3 μm. The laser displayed superior static performance including very low threshold current (~8 mA), high external quantum efficiency (0.44 mW/mA), high CW output power (>60 mW) and high temperature operation     

Singlemode Er:Yb waveguide laser array at 1.5 μm

An array of waveguide lasers operating at 1533 nm has been fabricated on Er:Yb-doped glass substrate by the silver-sodium ion-exchange technique. The maximum single-frequency output power from a single channel is 0.8 mW, with a relative intensity noise of -82 dB/Hz at the relaxation oscillation peak and below approximately -150 dB/Hz for frequencies higher than 2 MHz     

AlGaInAs/InP 1.5 μm MQW DFB laser diodes exceeding 20 GHzbandwidth

Buried mushroom multiquantum well DFB laser diodes with compressively strained GaInAs quantum wells and asymmetric confinement layer design are fabricated with a combined MBE/MOCVD technology. Packaged devices exhibit high -3 dB IM bandwidths for very low bias levels and a record bandwidth for this material system of 21 GHz     

15 W diode-side-pumped Tm:YAG waveguide laser at 2 μm

The high-power side-pumped operation of a double-clad Tm:YAG waveguide laser at 2.02 μm, using two proximity-coupled 20 W diode pump lasers, is reported. A slope efficiency of 43% was observed with respect to incident diode power, giving a maximum output power of 15 W. The double-clad geometry ensures diffraction-limited output in the guided plane     

GaInAsN/GaAs laser diodes operating at 1.52 μm

GaInAsN/GaAs double quantum well (DQW) lasers have been grown by solid source molecular beam epitaxy (MBE). Room-temperature pulsed operation is demonstrated for a ridge waveguide laser diode at a wavelength of 1517 nm. This is the first report of room-temperature laser emission in the 1.5 μm range based on GaAs     

All-binary InAs/GaAs optical waveguide phase modulator at 1.06μm

We demonstrate the use of multiple [(InAs) (GaAs)]/GaAs short-period strained-layer superlattice quantum wells for optical waveguide modulation at 1.06 μm. We achieve π phase modulation with 2.3 V applied (V_π×L=4.6 V mm, or 39°/V mm) in the presence of negligible absorption change using this all-binary modulator     

High-speed performance of OMCVD grown InAlAs/InGaAs MSMphotodetectors at 1.5 μm and 1.3 μm wavelengths

A report is presented on the fabrication of high-speed In_0.53 Ga_0.47As metal-semiconductor-metal (MSM) photodetectors incorporating a high-quality lattice-matched InAlAs barrier enhancement layer, grown by organometallic chemical vapor deposition (OMCVD). Fast responses of ~55 ps full-width half-maximum at 1.5 μm and ~48 ps at 1.3 μm wavelengths are observed, corresponding to intrinsic device bandwidths of ~8 GHz and ~11 GHz, respectively. The absence of any tail to the pulse response, and of any low-bias DC gain, indicates a low-trap density at the InAlAs/InGaAs heterointerface. Bias independent dark currents of 10-20 μA are observed below breakdown, which occurred at >30 V in devices with a 500-A-thick InAlAs layer     

Transfer-matrix dynamic model of partly gain-coupled 1.55 μm DFBlasers with a strained-layer MQW active grating

A dynamic model for partly gain-coupled 1.55 μm MQW DFB lasers consisting of etched strained-layer multiquantum wells is presented. For the modulation and noise characteristics of DFB lasers, analytical expressions which take into account both the longitudinal distribution of laser parameters and carrier transport effects are derived for the first time using the transfer-matrix method. As a numerical example, the relaxation oscillation frequency is compared to experimental results, and reasonable agreements are obtained between the theory and experiment     

Bandwidth-limited, single longitudinal mode ps optical pulsegeneration from a strongly Re-modulated distributed feedback GaInAsPdiode laser at 1.54 μm

Bandwidth-limited, single longitudinal mode ultrashort optical pulse generation from a GaInAsP DFB diode laser at 1.54 μm was realised for the first time using the simplest method of strong RF modulation superimposed on the controlled DC bias current. A typical time-bandwidth product of 0.44 with a FWHM of about 37.5 ps at 500 MHz modulation, proves quasi-Lorentzian shaped optical pulses of excellent coherent character     

Numerical simulation of a silicon-on-insulator waveguide structurefor phase modulation at 1.3 μm

This paper presents an analysis of a silicon-on-insulator (SOI) waveguide structure to be used for phase modulation at 1.3 μm. The device consists of a two-dimensional (2-D) strip waveguide and a p⁺ /N^-/N⁺ lateral diode to realize the effective index modulation by free-carrier injection. We have calculated that an effective index modulation between 5·10^-4 and 10^-3 could be obtained with current densities in the range from 500 to 1600 A/cm². A detailed numerical simulation of the device transient response is also reported. We demonstrate that an effective index modulation of 5·10^-4 could be obtained with a cutoff frequency of about 100 MHz. The phase modulator has a predicted figure-of-merit (FoM) of 160°/V/mm and a chirp factor of 25. Due to its full compatibility with complementary metal-oxide-semiconductor (CMOS)-SOI technology, the device is interesting for low-cost silicon-based optoelectronic systems     

Lasing at 2·08 μm and 1·38 μm in a holmiumdoped fluoro-zirconate fibre laser

The authors report for the first time a fibre laser operating beyond the 1·55 μm communications window. Using a holmium doped fluoro-zirconate fibre, laser emission occurs from the three-level 2·08 μm transition, and also at 1·38 μm via a cascading transition     

Performance characteristics of a 1.5 μm single-frequencysemiconductor laser with an external waveguide Braff reflector

Single-frequency operation of 1.5-μm semiconductor lasers was obtained by combining a regular Fabry-Perot laser to an external waveguide Bragg reflector. The laser is characterized by very pure single-frequency operation, 10-MHz linewidth, and greatly-reduced frequency chirp under direct modulation. The laser has been tested in 1.7-Gb/s transmission experiments over 82.5 km of fiber     

Well number, length, and temperature dependence of efficiency andloss in InGaAsP-InP compressively strained MQW ridge waveguide lasers at1.3 μm

Experimental measurements of external differential efficiency on 0.7% compressively strained multiquantum-well (MQW) ridge waveguide lasers operating at 1.3 μm are presented. The lasers have the number of quantum wells (QW's) varying from 5 to 14 and cavity lengths ranging from 250 to 1000 μm and were measured over a temperature range of -50°C to 90°C. A phenomenological model is introduced which shows that over a range of design and operating conditions, the behavior of the external differential quantum efficiency can be entirely explained by intervalence band absorption (IVBA) It is also shown that outside this range IVBA alone is not sufficient to describe the behavior, indicating that current leakage becomes a significant factor. Ramifications of the IVBA contribution to the external differential quantum efficiency are investigated     

Wannier-Stark localization in a 1.55 μm InGaAs/InAlAssuperlattice waveguide modulator structure

The authors present an optical waveguide modulator structure based on Wannier-Stark localization in a InGaAs-InAlAs superlattice. Optical waveguide transmission below the superlattice bandgap displays expected F^-1 oscillatory behavior leading to various modulation schemes. An 11 dB extinction ratio was obtained by applying a 0.7 V drive voltage to a 100 μm long waveguide device operating at 1.55 μm under a transverse-electric (TE)-polarization mode. On-state attenuation was 5 dB. Lower open-state attenuation (3 dB) can be obtained simultaneously with a higher extinction ratio (13 dB) but in that case a larger drive voltage (1.6 V) is needed     

Finite-difference time-domain analysis of microwave circuit deviceson high performance vector/parallel computers

In this paper, an efficient finite-difference time-domain algorithm for high performance distributed memory vector/parallel computers is presented. The algorithm is developed in a manner which requires only one interprocessor communication per time step. Illustrated examples based on the analysis of microwave circuit devices are presented demonstrating the efficiency and scalability of the finite-difference time-domain algorithm     

Wideband and high-power compressively strained GaInAsP/InPmultiple-quantum-well ridge waveguide lasers emitting at 1.3 μm

Compressively strained 1.3-μm GaInAsP/InP multiple-quantum-well (MQW) ridge waveguide lasers were fabricated. Through optimizing the total well thickness, large bandwidth over 11 GHz was achieved, together with high quantum efficiency of about 0.48 W/A and high power output of 60 mW before rollover. The laser also showed less temperature sensitivity up to an elevated temperature of 85°C     

Inverter performance of 0.10 μm CMOS operating at roomtemperature

The switching performance of 0.10 μm CMOS devices operating at room temperature has been discussed on the basis of both experimental and simulated results. The measured propagation delay time of a 0.10 μm gate length CMOS has been quantitatively divided into intrinsic and parasitic components for the first time. The results have shown that the drain junction capacitance strongly affects the propagation delay time in the present 0.10 μm CMOS. The switching performance of a 0.10 μm ground rule CMOS has been simulated by using device parameters extracted from the experimental results. In the 0.10 μm ground rule CMOS, it has been shown that an increase of the contact resistance will degrade the propagation delay time, which is one of the most essential problems in further device miniaturization. It has been also demonstrated that even if the specific contact resistance ρ_c is reduced to be less than 1×10^-7 Ω cm, further reduction of the gate overlap capacitance C_ov will be required to achieve the propagation delay time to be less than 10 ps in the 0.10 μm ground rule CMOS at room temperature     

Frequency stabilization of laser diodes at 0.83 μm using a fiberoptic coupler

Frequency stabilization of a fiber pigtailed laser diode discriminator is reported. The fiber coupler acts as a nearly-balanced-arm Michelson interferometer. The peak transmission signal is used for feedback control of the injection current of the laser diode. Because the sensing port can be isolated from the signal transmission port, the package design is very simple and can be implemented in an all-fiber fashion. The frequency fluctuation of a 0.83-μm test laser stabilized by this method is less than ±4 MHz. This scheme is applicable to longer-wavelength (1.2-1.6 μm) laser diodes; the stabilized lasers can be packaged easily     

Photoluminescence decay of 1.54 μm Er3+ emission inSi and III-V semiconductors

The luminescence lifetime of the 1.54 μm Er³⁺ emission has been studied in a variety of Si and III-V semiconductor host materials. The ≈1 millisecond lifetimes observed in all hosts indicate that the Er emission is largely radiative, and suggests that Er may be the rare earth dopant best suited for device applications. Additional competing nonradiative effects are seen to appear for certain growth conditions