Herve P. LeBlanc

High-temperature continuous-wave operation of low power consumption single-mode distributed-feedback quantum-cascade lasers at λ∼5.2 μm

Continuous-wave operation of a distributed-feedback quantum-cascade laser in a packaged module is demonstrated up to a heat sink temperature of 80 °C with an output power of greater than 10 mW and a power consumption of less than 3.8 W. Single longitudinal mode emission near 5.24 μm is observed over a temperature range from 10 to 80 °C with a side mode suppression ratio greater than 20 dB limited by the instrumentation. A single spatial mode is determined with far-field pattern measurement. The above performance is achieved using a buried heterostructure and a small cavity of 7.6 μm×1.5 mm.

Room Temperature CW Operation of Short Wavelength Quantum Cascade Lasers Made of Strain Balanced Ga

We present our recent development of short wavelength quantum cascade lasers (QCLs) made of strain balanced Ga_xIn_1-xAs/Al_yIn_1-yAs material on InP substrates. We demonstrate room temperature continuous-wave (CW) lasing of the fundamental lateral mode at four wavelengths of 4.6, 4.0, 3.8, and 3.5 μm. We obtained 60-mW CW output power at 10 °C and 3.55-μm wavelength, which is the shortest CW lasing wavelength demonstrated at room temperature by a QCL, to the best of our knowledge. We also performed a life test on λ = 4.6 μm QCL chips. To date, we have accumulated the life test data for more than 11 000 and 4100 h under two aging conditions, 20°C and 0.85-A constant current, and 60°C and 1-A constant current, respectively.

_{\bm x}

In this paper, watt-level continuous-wave (CW) output powers at wavelengths longer than 10 μm are demonstrated at room temperature with quantum cascade lasers (QCLs). CW output power of 1.15 W is demonstrated at λ ~ 10.3 μm for a QCL which has a 6-mm-long cavity and a 14-μm-wide stripe. CW output power of 1.3 W is demonstrated at λ ~ 10.7 μm for a QCL which has 6-mm-long cavity and 11.5-μm width, with a CW threshold current of 1.96 kA/cm². Moreover, 1-W kink-free CW output power is demonstrated with a laser with a 9.5-μm-wide stripe. The maximum pulsed and CW wall plug efficiencies reached 10.4% and 4.8%, respectively, for the QCLs with λ ~ 10.7 μm.

In

We present the design and the performance of midinfrared distributed feedback (DFB) quantum cascade lasers (QCLs) made of strain balanced Ga_xIn_1-xAs/Al_yIn_1-yAs material on InP substrates for sensing CO₂, N₂O, and NO in the middle wavelength range of mid-IR from 4 to 6 μm. We present the performances of our DFB QCLs at three different aspects: high power, low threshold power consumption, and wide wavelength coverage. We demonstrated a continuous wave (CW) DFB QCL with an output power of 220mW at 20°C, a CW DFB QCL with low threshold voltage of 8V and low-divergent far-field angles of 27.5° × 32.9° by reducing the number of quantum cascaded stages, a CW DFB QCL with a low threshold power consumption of 0.7W by reducing doping density in the active core, and DFB QCLs wide wavelength coverage of 325 cm^-1, 16.9% of center wavelength at 5.2 μm, within one wafer by changing the grating period. 12 DFB QCL chips have being aged for 3000 h under 25°C and a constant quasi-CW current of 0.37 A. No decrease in power was observed.

_{\bm {1-x}}

We report the life test results for 9 4.6-µm planar buried heterostructure quantum cascade lasers made of strain-balanced GaInAs/AlInAs/InP materials grown by metal organic vapor-phase epitaxy. No facet coating was deposited, and the devices were mounted on CuW submounts using AuSn solder. The aging condition is continuous wave operation at a heat-sink temperature of 22 o C with a constant current of 0.85A, corresponding to current densities of 4.7 and 2.7 kA/cm 2 , for lasers with widths of 4 and 7 µm, respectively. All lasers survived 5000 h aging, and most devices showed improved performance during the first 1000 h of aging.

As/Al

We present the design and the performance of mid-infrared distributed feedback quantum cascade lasers made of strain-balanced GaxIn1-xAs/AlyIn1-yAs material on InP substrates for wavelength near 5 μm. By changing the grating period within one wafer, we demonstrated wide wavelength coverage of 325 and 282 cm-1 (16.3% and 14.1% of the center wavelength) under room temperature pulsed and continuous wave (CW) operation, respectively. The variation of pulsed and CW laser performance as a function of wavelength detuning from the gain peak was studied and correlated to the amplified spontaneous emission spectra. We conclude that a slight positive detuning within 5% of the center wavelength favors CW performance especially for high-temperature operation.

_{\bm y}

Summary form only given. This paper reports the realization, for the first time, of a polarization-independent InP-based arrayed waveguide filter that has low internal loss, large fabrication tolerances, and may operate over the entire 1.5-/spl mu/m fiber band. It also provides high cross talk suppression and has been realized with a very compact die-size.

In

This paper presents recent progress on SOAs with dilute optical mode. The SOA optical mode is designed to be large to achieve high saturation power and low coupling losses of 1.16 and 0.89 dB for TE and TM polarizations with a lens fiber. A 2-mm long SOA has high saturation power (16.3 dBm), low PDG (<1 dB), low noise figure (<7.2 dB) and medium gain (>19.5 dB) across C-band. A 1.5mm-long SOA was successfully used as a 10 Gbit/s booster amplifier for 100km transmission. The dynamic properties of the SOA were characterized to support application as optical gate switch in sub GHz speed.

_{\bm {1-y}}

We demonstrated the room temperature continuous wave (CW) operation of mid-infrared distributed feedback (DFB) quantum cascade lasers (QCLs) made of strain balanced GaInAs/AlInAs material on InP substrates for sensing CO2 isotope and N2O gas for potential applications that need battery powered portable devices in a sensor network. For the former device at 4.35 μm wavelength, we demonstrated a low threshold voltage of less than 8 V for battery operation and a near circular far field pattern with small divergent angles of 33 by 28 degrees full width at half maximum (FWHM) in vertical and horizontal directions, respectively, for easy collimation. For the latter device at 4.5 μm wavelength, we demonstrated a low CW threshold power consumption of 0.7 W at 20 °C. A side mode suppression ratio (SMSR) of 30 dB was achieved within the whole operating current and temperature ranges for both lasers.

As Material on InP Substrates

We characterized the performance of sampled-grating distributed Bragg reflectors (SG DBR) quantum cascade lasers (QCLs) and demonstrated a wide wavelength tuning from 4.48 to 4.69 μm (100cm-1) by injecting current into the SGDBR sections.