Observation of room temperature surface‐emitting stimulated emission from GaN:Ge by optical pumping

1996 ◽  
Vol 80 (11) ◽  
pp. 6544-6546 ◽  
Author(s):  
X. Zhang ◽  
P. Kung ◽  
A. Saxler ◽  
D. Walker ◽  
M. Razeghi
Author(s):  
В.Я. Алешкин ◽  
Н.В. Байдусь ◽  
А.А. Дубинов ◽  
К.Е. Кудрявцев ◽  
С.М. Некоркин ◽  
...  

AbstractThe mode of the growth of InGaAs quantum dots by MOS-hydride epitaxy on GaAs substrates without a deviation and with a deviation of 2° is selected for laser structures emitting at wavelengths above 1.2 μm at room temperature. As a result, a quantum-dot density of 4 × 10^10 cm^–2 is achieved. Stimulated emission is observed in laser structures with seven layers of quantum dots at a wavelength of 1.06 μm at liquid-nitrogen temperature. The threshold power density of optical pumping is about 5 kW/cm^2.


1994 ◽  
Vol 339 ◽  
Author(s):  
I. Akasaki ◽  
H. Amano

ABSTRACTHigh-quality AlGaN/GaN and AlGaN/GalnN DHs were fabricated by MOVPE using low-temperature deposited AlN buffer layer. We applied the newly designed dual-flow-channel reactor, by which high-quality and well-controlled AlGaN and GalnN alloys and their heterostructures have been grown. AlGaN/GaN-DH shows low-threshold stimulated emission by optical pumping at room temperature for both edge and surface modes. The peak wavelength of stimulated emission for edge mode was 369.5nm. The peak wavelength of stimulated emission was affected by the strain due to heterostructure as well as the many body effect under high excitation. The wavelength for stimulated emission can be widely changed by using GalnN as the active layer. AlGaN/GalnN DH with InN molar fraction of the active layer of 0.09 shows room temperature low-threshold stimulated emission for edge mode by optical pumping with peak wavelength of 402.5nm. A few mW-class symmetrical AlGaN/GaN DH LED and anti symmetrical AlGaN/GalnN/GaN DH LED using low energy electron beam irradiation (LEEB1) treated Mg-doped P-AlGaN cladding layer were fabricated. These results show that column-Ill nitrides are promising for the realization of practical short wavelength LED and LD.


1993 ◽  
Vol 32 (Part 2, No. 7B) ◽  
pp. L1000-L1002 ◽  
Author(s):  
Hiroshi Amano ◽  
Nobuaki Watanabe ◽  
Norikatsu Koide ◽  
Isamu Akasaki

1995 ◽  
Vol 395 ◽  
Author(s):  
Hiroshi Amano ◽  
Shigetoshi Sota ◽  
Masaki Nishikawa ◽  
Masato Yoshida ◽  
Makoto Kawaguchi ◽  
...  

ABSTRACTAlGaN/GalnN double heterostructures (DH) were fabricated by metalorganic vapor phase epitaxy on the (0001)Si 6H-SiC substrate. A cleaved edge shows a very flat surface with roughness on the order of one monolayer. Stimulated emission and laser action from the UV to blue region was observed by optical pumping at room temperature (RT). The threshold power density was 27KW/cm2 which is smaller than that of the same structure grown on a sapphire (0001) substrate by a factor of four. A AlGaN/GalnN DH UV light emitting diode, using undoped GalnN is fabricated. The power efficiency and spectra width of this LED is comparable or superior to that of an LED having the same structure but grown on sapphire.


Nanophotonics ◽  
2020 ◽  
Vol 9 (15) ◽  
pp. 4505-4518
Author(s):  
Sarath Raman Nair ◽  
Lachlan J. Rogers ◽  
Xavier Vidal ◽  
Reece P. Roberts ◽  
Hiroshi Abe ◽  
...  

AbstractLaser threshold magnetometry using the negatively charged nitrogen-vacancy (NV−) centre in diamond as a gain medium has been proposed as a technique to dramatically enhance the sensitivity of room-temperature magnetometry. We experimentally explore a diamond-loaded open tunable fibre-cavity system as a potential contender for the realisation of lasing with NV− centres. We observe amplification of the transmission of a cavity-resonant seed laser at 721 nm when the cavity is pumped at 532 nm and attribute this to stimulated emission. Changes in the intensity of spontaneously emitted photons accompany the amplification, and a qualitative model including stimulated emission and ionisation dynamics of the NV− centre captures the dynamics in the experiment very well. These results highlight important considerations in the realisation of an NV− laser in diamond.


Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 431
Author(s):  
Giorgio Turri ◽  
Scott Webster ◽  
Michael Bass ◽  
Alessandra Toncelli

Spectroscopic properties of neodymium-doped yttrium lithium fluoride were measured at different temperatures from 35 K to 350 K in specimens with 1 at% Nd3+ concentration. The absorption spectrum was measured at room temperature from 400 to 900 nm. The decay dynamics of the 4F3/2 multiplet was investigated by measuring the fluorescence lifetime as a function of the sample temperature, and the radiative decay time was derived by extrapolation to 0 K. The stimulated-emission cross-sections of the transitions from the 4F3/2 to the 4I9/2, 4I11/2, and 4I13/2 levels were obtained from the fluorescence spectrum measured at different temperatures, using the Aull–Jenssen technique. The results show consistency with most results previously published at room temperature, extending them over a broader range of temperatures. A semi-empirical formula for the magnitude of the stimulated-emission cross-section as a function of temperature in the 250 K to 350 K temperature range, is presented for the most intense transitions to the 4I11/2 and 4I13/2 levels.


2019 ◽  
Vol 11 (43) ◽  
pp. 40260-40266
Author(s):  
Kentaro Nakamura ◽  
Tsunaki Takahashi ◽  
Takuro Hosomi ◽  
Takehito Seki ◽  
Masaki Kanai ◽  
...  

2021 ◽  
Vol 7 (21) ◽  
pp. eabf8049
Author(s):  
Rui Su ◽  
Sanjib Ghosh ◽  
Timothy C. H. Liew ◽  
Qihua Xiong

Strong light-matter interaction enriches topological photonics by dressing light with matter, which provides the possibility to realize active nonlinear topological devices with immunity to defects. Topological exciton polaritons—half-light, half-matter quasiparticles with giant optical nonlinearity—represent a unique platform for active topological photonics. Previous demonstrations of exciton polariton topological insulators demand cryogenic temperatures, and their topological properties are usually fixed. Here, we experimentally demonstrate a room temperature exciton polariton topological insulator in a perovskite zigzag lattice. Polarization serves as a degree of freedom to switch between distinct topological phases, and the topologically nontrivial polariton edge states persist in the presence of onsite energy perturbations, showing strong immunity to disorder. We further demonstrate exciton polariton condensation into the topological edge states under optical pumping. These results provide an ideal platform for realizing active topological polaritonic devices working at ambient conditions, which can find important applications in topological lasers, optical modulation, and switching.


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