scholarly journals Radiation-Balanced Lasers: History, Status, Potential

2021 ◽  
Vol 11 (16) ◽  
pp. 7539
Author(s):  
Galina Nemova
Keyword(s):  
Theoretical Description ◽  
Stimulated Emission ◽  
Laser Medium ◽  
Rate Equations ◽  
Special Focus ◽  
Solid State Lasers ◽  
Optically Pumped ◽  
Improved Performance ◽  
Anti Stokes ◽  
Fluorescence Wavelength

The review of history and progress on radiation-balanced (athermal) lasers is presented with a special focus on rare earth (RE)-doped lasers. In the majority of lasers, heat generated inside the laser medium is an unavoidable product of the lasing process. Radiation-balanced lasers can provide lasing without detrimental heating of laser medium. This new approach to the design of optically pumped RE-doped solid-state lasers is provided by balancing the spontaneous and stimulated emission within the laser medium. It is based on the principle of anti-Stokes fluorescence cooling of RE-doped low-phonon solids. The theoretical description of the operation of radiation-balanced lasers based on the set of coupled rate equations is presented and discussed. It is shown that, for athermal operation, the value of the pump wavelength of the laser must exceed the value of the mean fluorescence wavelength of the RE laser active ions doped in the laser medium. The improved purity of host crystals and better control of the transverse intensity profile will result in improved performance of the radiation-balanced laser. Recent experimental achievements in the development of radiation-balanced RE-doped bulk lasers, fibre lasers, disk lasers, and microlasers are reviewed and discussed.

scholarly journals Superluminescence from an optically pumped molecular tunneling junction by injection of plasmon induced hot electrons

2015 ◽  
Vol 6 ◽  
pp. 1100-1106 ◽  
Author(s):  
Kai Braun ◽  
Xiao Wang ◽  
Andreas M Kern ◽  
Hilmar Adler ◽  
Heiko Peisert ◽  
...  
Keyword(s):  
Bias Voltage ◽  
Light Emitting Diode ◽  
Optical Signal ◽  
Stimulated Emission ◽  
Hole Injection ◽  
Rate Equations ◽  
Scanning Tunneling ◽  
Ambient Conditions ◽  
Optically Pumped ◽  
Optical Pump

Here, we demonstrate a bias-driven superluminescent point light-source based on an optically pumped molecular junction (gold substrate/self-assembled molecular monolayer/gold tip) of a scanning tunneling microscope, operating at ambient conditions and providing almost three orders of magnitude higher electron-to-photon conversion efficiency than electroluminescence induced by inelastic tunneling without optical pumping. A positive, steadily increasing bias voltage induces a step-like rise of the Stokes shifted optical signal emitted from the junction. This emission is strongly attenuated by reversing the applied bias voltage. At high bias voltage, the emission intensity depends non-linearly on the optical pump power. The enhanced emission can be modelled by rate equations taking into account hole injection from the tip (anode) into the highest occupied orbital of the closest substrate-bound molecule (lower level) and radiative recombination with an electron from above the Fermi level (upper level), hence feeding photons back by stimulated emission resonant with the gap mode. The system reflects many essential features of a superluminescent light emitting diode.

Ultraviolet Stimulated Emission From Optically Pumped AlGaN/AlGaN Multiple Quantum Wells on Pulsed Laterally Overgrown $a$-Plane GaN

2011 ◽  
Vol 4 (8) ◽  
pp. 082103 ◽  
Author(s):  
Mohamed Lachab ◽  
Krishnan Balakrishnan ◽  
Bin Zhang ◽  
Joe Dion ◽  
Qhalid Fareed ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Stimulated Emission ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Optically Pumped

Stimulated emission at 257 nm from optically-pumped AlGaN/AlN heterostructure on AlN substrate

2013 ◽  
Vol 210 (9) ◽  
pp. 1768-1770 ◽  
Author(s):  
Zachary Lochner ◽  
Xiao-Hang Li ◽  
Tsung-Ting Kao ◽  
Md. Mahbub Satter ◽  
Hee Jin Kim ◽  
...  
Keyword(s):  
Stimulated Emission ◽  
Optically Pumped

Optimization of concentration and length of laser medium in diode-end-pumped solid-state lasers considering energy-transfer-upconversion effects

Optik ◽  
2013 ◽  
Vol 124 (13) ◽  
pp. 1445-1449 ◽  
Author(s):  
Yaoting Wang ◽  
Wujun Li ◽  
Leilei Pan ◽  
Jintao Yu ◽  
Ruihong Zhang
Keyword(s):  
Energy Transfer ◽  
Solid State ◽  
Laser Medium ◽  
Solid State Lasers ◽  
Energy Transfer Upconversion

Terahertz light amplification by stimulated emission of radiation from optically pumped graphene

2011 ◽  
Author(s):  
Taiichi Otsuji ◽  
Stephane A. Boubanga Tombet ◽  
Silvia Chan ◽  
Akira Satou ◽  
Victor Ryzhii
Keyword(s):  
Stimulated Emission ◽  
Optically Pumped ◽  
Light Amplification

High-Power Low-Threshold Optically Pumped Type-ll Quantum-Well Lasers

1997 ◽  
Vol 484 ◽  
Author(s):  
Chih-Hsiang Lin ◽  
S. J. Murry ◽  
Rui Q. Yang ◽  
S. S. Pei ◽  
H. Q. Le ◽  
...  
Keyword(s):  
Quantum Well ◽  
Output Power ◽  
Optical Pumping ◽  
Internal Quantum Efficiency ◽  
Characteristic Temperature ◽  
Stimulated Emission ◽  
Free Carrier Absorption ◽  
Type Ii ◽  
Optically Pumped ◽  
Internal Loss

AbstractStimulated emission in InAs/InGaSb/InAs/AlSb type-II quantum-well (QW) lasers was observed up to room temperature at 4.5 μm, optically pumped by a pulsed 2-μm Tm:YAG laser. The absorbed threshold peak pump intensity was only 1.1 kW/cm2 at 300 K, with a characteristic temperature T0 of 61.6 K for temperatures up to 300 K. We will also study the effects of internal loss on the efficiency and output power for type-II QW lasers via optical pumping. Using a 0.98-μm InGaAs linear diode array, the devices exhibited an internal quantum efficiency of 67% at temperatures up to 190 K, and was capable of < 1. 1-W peak output power per facet in 6-μs pulses at 85 K. The internal loss of the devices exhibited an increase from 18 cm−1 near 70 K to ∼ 60–100 cm−1 near 180 K, which was possibly due to inter-valence band free carrier absorption.

Molecular Beam Epitaxy of Znl-x Cdx Se/ZnSe Heterostructures And Their Optical Properties

1991 ◽  
Vol 228 ◽  
Author(s):  
H. Luo ◽  
N. Samarth ◽  
J. K. Furdyna ◽  
H. Jeon ◽  
J. Ding ◽  
...  
Keyword(s):  
Optical Properties ◽  
Molecular Beam Epitaxy ◽  
Quantum Wells ◽  
Room Temperature ◽  
Molecular Beam ◽  
Stimulated Emission ◽  
Optically Pumped ◽  
Absorption Coefficients ◽  
Excitonic Absorption ◽  
Lasing Mechanism

ABSTRACTSuperlattices and quantum wells of Znl-xCdxSe/ZnSe, and heterostructures based on ZnSe/CdSe digital alloys have been grown by molecular beam epitaxy (MBE). Their optical properties were studied with particular emphasis on excitonic absorption and photopumped stimulated emission. Excitonic absorption is easily observable up to 400 K, and is characterized by extremely large absorption coefficients (α = 2×105cm−1). Optically pumped lasing action is obtained at room temperature with a typical threshold intensity of 100 kW/cm2. The lasing mechanism in these II-VI quantum wells appears to be quite different from that in the better studied III-V materials: in our case, the onset of stimulated emission occurs before the saturation of the excitonic absorption, and the stimulated emission occurs at an energy lower than that of the excitonic absorption.

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