Publications by Vladimir Iakovlev

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We present an efficient method to model the small-signal modulation response of a long-wavelength VCSEL chip using an equivalent electrical circuit. This circuit serves two distinct purposes. Based on T-Matrix formalism, it is used to remove the parasitics ...

We report on a semiconductor disk laser emitting 1.5 W of output power at the wavelength of 745 nm via intracavity frequency doubling. The high power level and the >40 nm tuning range make the laser a promising tool for medical treatments that rely on phot ...

An electrically pumped VCSEL (10) and a method of its fabrication are presented. The VCSEL (10) comprises an active cavity material (14) sandwiched between top and bottom DBR stacks (12a, 12b), the top DBR (12b) having at least one n-semiconductor layer. The device defines an aperture region (25) between the structured surface (14b) of the active cavity material (14) and the n-semiconductor layer of the top DBR stack (12b). The structured surface (14b) is formed by a top surface of a mesa (22) that includes

A widely-tunable single-mode 1.3 mu m vertical-cavity surface-emitting laser structure incorporating a microelectromechanical system-tunable high-index-contrast subwavelength grating (HCG) mirror is suggested and numerically investigated. A linear tuning r ...

We report coupled VCSEL arrays, emitting at 1.3μm wavelength, in which both the optical gain/loss and refractive index distributions were defined on different vertical layers. The arrays were electrically pumped through a patterned tunnel junction, whereas the array pixels were realized by intra-cavity patterning using sub-wavelength air gaps. Stable oscillations in coupled modes were evidenced for 2x2 array structures, from threshold current up to thermal roll-over, using spectrally resolved field pattern

1300-nm, 1550-nm and 1480-nm wavelength, optically-pumped VECSELs based on wafer-fused InAlGaAs/InPAlGaAs/GaAs gain mirrors with intra-cavity diamond heat-spreaders demonstrate very low thermal impedance of 4 K/W. Maximum CW output of devices with5 groups ...

Vertical-cavity surface-emitting laser (VCSEL)-by-VCSEL optical injection locking to obtain high cutoff frequencies of 1.3-mu m VCSELs is demonstrated. A detailed physical explanation of the underlying mechanism is presented. VCSELs from the same wafer have been used in a master-follower configuration. Two probe stations are used in this experiment to power-up two VCSELs simultaneously. Polarization insensibility of the injection locking is demonstrated and a novel architecture is proposed to achieve cutoff

We review recent results on wafer fused long wavelength VCSELs emitting in the 1310 - 2000 nm range. This technology allows reaching fundamental mode output in excess of 4.5 mW at room temperature and close to 3 mW at 70 degrees C for both the 1310 nm and 1550 nm wavebands-the highest values obtained so far. Emission wavelength can be tuned continuously with current with a tuning range as large as 15 nm. For 2000 nm emission wavelength, room temperature output is similar to 0.5 mW, limited so far by high op

We present 6.1 W of output power from a flip-chip semiconductor disk laser (SDL) emitting in the 1.3 mu m wavelength region. This is the first demonstration of a flip-chip SDL in this wavelength range with output powers that are comparable to those obtaine ...

Optically pumped wafer fused 1310 nm VECSELs have the advantage of high output power and wavelength agility. Gain mirrors in these lasers are formed by direct bonding of InAlGaAs/InP active cavities to Al(Ga) As/GaAs DBRs. We present for the first time Wat ...

Digital chemical etching is used to trim the output mirror thickness of wafer-fused VCSELs emitting at a wavelength near 1.5 mu m. The fine control of the photon cavity lifetime thus achieved is employed to extract important device parameters and optimize ...

Chemical beam epitaxy (CBE) grown InAsP/InGaAsP edge-emitting laser diodes on GaAs substrates obtained by localised fusion in a nitrogen environment exhibit high quality fused interfaces. A degradation of fused lasers is observed which is attributed to the disordering of quantum wells at fusion temperatures induced by point defects incorporated during low temperature growth.

We investigate experimentally the impact of photon cavity lifetime variations on the static and dynamic performance of high-speed 1.3-mu m wavelength wafer-fused vertical-cavity surface-emitting lasers (VCSELs). The photon lifetime is modified by decreasin ...

1310 nm Wavelength VCSELs produce single mode emission in excess of 1 mW in the temperature range of 20-70 degrees C with a very low relative intensity noise of -148 dB/Hz. These devices have a broad tuning range of similar to 50 cm(-1) with variable tempe ...

We report on fabrication and performance of wafer fused, high power, passively mode-locked semiconductor disc lasers operating in 1310 nm and 1550 nm bands. These devices comprise gain mirrors based on InAlGaAs/InP multi quantum well active regions fused t ...

We report record-high fundamental mode output power of 8 mW at 0 °C and 1.5 mW at 100°C achieved with wafer-fused InAlGaAs-InP/AlGaAs-GaAs 1550 nm VCSELs incorporating a re-grown tunnel junction and un-doped AlGaAs/GaAs distributed Bragg reflectors. A broad wavelength tuning range of 15 nm by current variation and wavelength setting in a spectral range of 40 nm on the same VCSEL wafer are demonstrated as well. This performance positions wafer-fused VCSELs as prime candidates for many applications in low pow

An output power up to 5 W at 1.48- m wavelength is achieved from an optically pumped semiconductor disk laser. An active region composed of an AlGaInAs/InP heterostructure grown on an InP substrate was wafer fused with an AlGaAs/GaAs Bragg reflector grown on a GaAs substrate. An intracavity diamond heatspreader bonded to the gain structure surface provides efficient heat removal from the active element. The results further validate that the wafer fusion technique offers a flexible platform for high-power di

We report on transverse mode discrimination in long-wavelength wafer-fused vertical-cavity surface-emitting lasers (VCSELs) incorporating ring-shaped air gap patterns at the fused interface between the active region and the top distributed Bragg reflector (DBR). These 60-nm deep patterns were implemented with the aim of favoring the fundamental mode while preserving high output power. The VCSELs under consideration emit in the 1310-nm band and incorporate an AlGaInAs-based quantum well active region, a regr

Photoluminescence intensity and emission wavelength of InAsP/InGaAsP and InGaAs/InGaAsP multi-quantum well (MQW) laser structures grown by chemical beam epitaxy (CBE) at 460 degrees C and V/III ratio of 2 are considerably affected by annealing at temperatures 600-650 degrees C which prevents lasing of these structures fused on GaAs substrates. It is shown that the degradation of luminescence characteristics can be decreased by increasing the growth temperature to 480 degrees C and V/III ratio to 4. InAsP/In

We report the fabrication and the performance of phase-locked VCSEL arrays emitting near 1310 nm wavelength. The arrays were fabricated using double wafer fusion by patterning a tunnel junction layer, which serves to define the individual single mode array elements. Phase-locking in both one-dimensional and two-dimensional array configurations was confirmed by means of far field and spectral measurements as well as theoretical modeling. CW output powers of more than 12 mW were achieved. (C) 2009 Optical Soc

Vladimir Iakovlev

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Electrical Modeling of Long-Wavelength VCSELs for Intrinsic Parameters Extraction

A 1.5-W frequency-doubled semiconductor disk laser tunable over 40 nm at around 745 nm

Vertical cavity surface emitting laser

Broadband MEMS-Tunable High-Index-Contrast Subwavelength Grating Long-Wavelength VCSEL

Intra-cavity patterning for mode control in 1.3μm coupled VCSEL arrays

High-power optically-pumped VECSELs emitting in the 1310-nm and 1550-nm wavebands

Long Wavelength VCSL-by-VCSEL Optical Injection Locking

Recent Developments in Long Wavelength VCSELs Based on Localized Wafer Fusion

High-power flip-chip semiconductor disk laser in the 1.3 μm wavelength band

Wafer-fused VECSELs emitting in the 1310 nm waveband

Control of cavity lifetime of 1.5 mu m wafer-fused VCSELs by digital mirror trimming

Characteristics of InAsP/InGaAsP Edge Emitting Laser Diodes Obtained by Localised Fusion on GaAs Substrates

Effect of Cavity Lifetime Variation on the Static and Dynamic Properties of 1.3-μm Wafer-Fused VCSELs

Near-infrared wafer-fused vertical-cavity surface-emitting lasers for HF detection

Wafer-Fused 1310 nm and 1550 nm Mode-Locked Semiconductor Disk Lasers

8 mW fundamental mode output of wafer-fused VCSELs emitting in the 1550-nm band

High-Power 1.48-μm Wafer-Fused Optically Pumped Semiconductor Disk Laser

Improved single-mode emission characteristics of long-wavelength wafer-fused vertical-cavity surface-emitting lasers by intra-cavity patterning

Thermal Stability of InP-Based Structures for Wafer Fused Laser Diodes

1.3µm-wavelength phase-locked VCSEL arrays incorporating patterned tunnel junction