The performance of a high-power single-mode InGaAs QD-based BOA providing 28dBm of output saturation power in 25÷85°C temperature range is presented. The studied BOA is targeted for 1.3μm LIDAR applications working in uncooled regime.

High-power O-band Quantum Dot Distributed-Feedback Laser for pluggable DR4/DR8 optical transceivers and Remote Laser Modules is presented. It exhibits PCE as high as 20% up to 105°C and CW power exceeding 300mW at 85°C.

We have investigated two-sectional semiconductor lasers with an active region comprising five layers of InGaAs quantum dots, emitting in the spectral range near 1.06 μm. Regimes of passive mode-locking, passive Q-switching, and mode-locking with pulse modulated amplitude are realized. The transition conditions between generation regimes are investigated. The frequency tuning range with current increase in the Q-switched regime exceeds more than 4 times. The duration of the mode-locked pulses was 2 ps at the pulse repetition rate of 44.3 GHz.

AbstractWe have investigated two-sectional semiconductor lasers with an active region comprising five layers of InGaAs quantum dots, emitting in the spectral range near 1.06 μm. Regimes of passive mode-locking, passive Q-switching, and mode-locking with pulse modulated amplitude are realized. The transition conditions between generation regimes are investigated. The frequency tuning range with current increase in the Q-switched regime exceeds more than 4 times. The duration of the mode-locked pulses was 2 ps at the pulse repetition rate of 44.3 GHz.

We propose a model for operation of mode-locked (ML) quantum-well semiconductor laser consisting of a reverse biased saturable absorber and a forward biased amplifying section. To describe the dynamics of this laser we use the traveling wave model. Numerical simulations performed for the InGaAs/InGaAlAs laser structure emitting at 1,55 um.

We propose a model of passive mode-locking laser diode based on quantum wells. Numerical results for InGaAlAs/InGaAs/InP heterostructure with 4 quantum wells in active region are presented. The dynamics of the transition to mode-locking has been investigated. It has been shown that mode-locking occurs approximately within 30 ns. The pulse duration was amounted to 2 ps, average output power to 9.4 mW. The appearance of the second harmonic radiation in the resonator is connected to the insufficient absorber relaxation rate.

The passive Q-switching and mode-locking modes are implemented in two-section lasers with three quantum wells. It is demonstrated that raising the reverse bias on the absorbing section changes its spectral and dynamic properties and, accordingly, leads to a change from the Q-switching mode to mode-locking. The pulse-repetition frequency in the mode-locking mode is 75 GHz, with the product of the pulse duration by the spectrum bandwidth being 0.49, which is close to the theoretical limit. It is shown that, in structures with three quantum wells, strong absorption at the lasing wavelength gives rise to a photocurrent across a section of the saturable absorber, which is sufficient for compensation of the applied bias.

Two-sectional laser diodes emitting light pulses in Q-switched (QS) mode are investigated. The active region of lasers contains three quantum wells. The shift of absorption edge due to Stark effect leads to red shift of lasing wavelength and pulse power doubling in QS mode.

The Stark effect has been studied in multilayer InGaAs/GaAs laser structures with self-assembled quantum dots (QDs). A shift in the absorption edge depending on the reverse bias voltage has been measured in a two-section laser diode. The QD absorption edge shifts toward longer wavelengths with increasing electric field strength. It is established that the QD absorption depends on the polarization of light. The intensity at which TE-polarized luminescence in laser structures is studied is more than ten times higher than that of the TE-polarized emission component, which is explained by higher amplification of the TE mode.

Ultrashort pulses of 1.7 ps at frequency as low as 9.7 GHz are demonstrated by passive mode-locking of monolithic two-section InAs/InGaAs (/spl lambda/=1.28 /spl mu/m) quantum-dot laser. Pulse shortening with the absorber section bias increase is observed.

The molecular beam epitaxy of self-assembled quantum dots (QDs) has reached a level such that the principal advantages of QD lasers can now be fully realized. We overview the most important recent results achieved to date including excellent device performance of 1.3 μm broad area and ridge waveguide lasers (Jth<150A/cm2, Ith=1.4 mA, differential efficiency above 70%, CW 300 mW single lateral mode operation), suppression of non-linearity of QD lasers, which results to improved beam quality, reduced wavelength chirp and sensitivity to optical feedback. Effect of suppression of side wall recombination in QD lasers is also described. These effects give a possibility to further improve and simplify processing and fabrication of laser modules targeting their cost reduction. Recent realization of 2 mW single mode CW operation of QD VCSEL with all-semiconductor DBR is also presented. Long-wavelength QD lasers are promising candidate for mode-locking lasers for optical computer application. Very recently 1.7-ps-wide pulses at repetition rate of 20 GHz were obtained on mode-locked QD lasers with clear indication of possible shortening of pulse width upon processing optimization. First step of unification of laser technology for telecom range with QD-lasers grown on GaAs has been done. Lasing at 1.5 μm is achieved with threshold current density of 0.8 kA/cm2 and pulsed output power 7W.

The near-threshold lasing regimes of AlGaAs lasers with an implanted saturated absorber under short pulsed pumping are investigated experimentally. A near-threshold modesynchronization regime is obtained.

A method of implanting high-energy heavy ions across the emitter layer of a semiconductor laser has been developed to create distributed regions of ultrafast saturable absorber integrated into the cavity of a quantum-well laser. This method was used to fabricate picosecond laser diodes having high average powers and to demonstrate colliding-pulse mode-locking of a diode laser with a multisection saturable absorber.