S. C. Huang

Room Temperature Current Injection Polariton Light Emitting Diode with a Hybrid Microcavity

The strong light-matter interaction within a semiconductor high-Q microcavity has been used to produce half-matter/half-light quasiparticles, exciton-polaritons. The exciton-polaritons have very small effective mass and controllable energy-momentum dispersion relation. These unique properties of polaritons provide the possibility to investigate the fundamental physics including solid-state cavity quantum electrodynamics, and dynamical Bose-Einstein condensates (BECs). Thus far the polariton BEC has been demonstrated using optical excitation. However, from a practical viewpoint, the current injection polariton devices operating at room temperature would be most desirable. Here we report the first realization of a current injection microcavity GaN exciton-polariton light emitting diode (LED) operating under room temperature. The exciton-polariton emission from the LED at photon energy 3.02 eV under strong coupling condition is confirmed through temperature-dependent and angle-resolved electroluminescence spectra.

AlGaInAs quantum-well 1.3-μm laser by a diode-pumped actively Q-switched Nd:GdVO4 laser

We report a high-peak-power AlGaInAs 1.36-μm vertical-external-cavity surface-emitting laser (VECSEL) optically pumped by a diode-pumped actively Q-switched Nd:GdVO4 1.06-µm laser under room-temperature operation. The gain medium is an AlGaInAs quantum wells (QWs)/barrier structure grown on a Fe-doped InP substrate by metalorganic chemical-vapor deposition. With an average pump power of 1.9 W, an average output power of 340 mW was obtained at a pulse repetition rate of 40 kHz, corresponding to an optical-to-optical conversion efficiency of 18.76%. With a peak pump power of 7.9 kW, the highest peak output power was 1.3 kW at a pulse repetition rate of 10 kHz.

Polariton lasing in a ZnO-based microcavity up to 353K

We report the polariton lasing at temperature up to 353K in a ZnO-based microcavity. The large exciton binding energy and Rabi-splitting of ZnO ensuring the strong coupling regime is maintained at high temperature.

GaN-based microcavity polariton light emitting diodes

Here we report the first realization of a current injection microcavity GaN exciton-polariton light emitting diode (LED) operating under room temperature (RT). The hybrid microcavity structure consists of InGaN/GaN quantum wells sandwiched between bottom epitaxial DBR and top dielectric DBR. The anti-crossing behavior of polariton LED denotes a clear signature of the strong interaction between excitons and cavity photons.

Low-temperature study of lasing characteristics for 1.3-μm AlGaInAs quantum-well laser pumped by an actively Q-switched Nd:YAG laser

We report a low-temperature 1.3μm AlGaInAs quantum-well laser pumped by a 1.06μm active Q-switched laser quenched by a low-temperature vacuum system. An average power of 330mW is achieved at temperature as low as 233K compared to the average power of 50mW obtained at room-temperature without cooling device both at pumping repetition rate of 30 kHz. And the average rate of gain peak shift was found to be 0.47 nm/K between 293-133 K.

AlGaInAs quantum-well saturable absorbers for a diode-pumped passively Q-switched Nd:YVO4 laser at 1064 nm

We report the use of AlGaInAs quantum wells (QWs) as a saturable absorber in the Q-switching of a high-power diode-pumped Nd-doped 1064nm laser. The barrier layers are designed to locate the QW groups in the region of the nodes of the lasing standing wave for avoiding damage. With an incident pump power of 22 W at 878nm, an average output power of 6.8 W with a Q-switched pulse width of 0.85 ns at a pulse repetition rate of 105kHz was obtained.

High-peak-power flashlamp-pumped passively Q-switched Nd:YAG laser with AlGaInAs quantum wells as a saturable absorber

We demonstrate an AlGaInAs saturable absorber with a periodic quantum wells (QWs)/barrier structure that can be used to achieve an efficient high-peak-power and high-pulse-energy passively flashlamp-pumped Q-switched Nd:YAG laser at 1.06 um. The barrier layers are designed to locate the QW groups in the region of the nodes of the lasing standing wave to avoid damage. With an incident pump voltage of 14.5 J, a single pulse was generated with a pulse energy of 14 mJ and a Q-switched pulse width of 13 ns. The maximum peak power was greater than 1.08 MW.