scholarly journals Superradiant lasing in inhomogeneously broadened ensembles with spatially varying coupling

2021 ◽  
Vol 1 ◽  
pp. 73
Author(s):  
Anna Bychek ◽  
Christoph Hotter ◽  
David Plankensteiner ◽  
Helmut Ritsch
Keyword(s):  
Optical Pumping ◽  
Spectral Width ◽  
Stimulated Emission ◽  
Optical Clock ◽  
Frequency Noise ◽  
Atomic Coherence ◽  
Atom Number ◽  
Large Bandwidth ◽  
Large Numbers ◽  
Spatially Varying

Background: Theoretical studies of superradiant lasing on optical clock transitions predict a superb frequency accuracy and precision closely tied to the bare atomic linewidth. Such a superradiant laser is also robust against cavity fluctuations when the spectral width of the lasing mode is much larger than that of the atomic medium. Recent predictions suggest that this unique feature persists even for a hot and thus strongly broadened ensemble, provided the effective atom number is large enough. Methods: Here we use a second-order cumulant expansion approach to study the power, linewidth and lineshifts of such a superradiant laser as a function of the inhomogeneous width of the ensemble including variations of the spatial atom-field coupling within the resonator. Results: We present conditions on the atom numbers, the pump and coupling strengths required to reach the buildup of collective atomic coherence as well as scaling and limitations for the achievable laser linewidth. Conclusions: We show how sufficiently large numbers of atoms subject to strong optical pumping can induce synchronization of the atomic dipoles over a large bandwidth. This generates collective stimulated emission of light into the cavity mode leading to narrow-band laser emission at the average of the atomic frequency distribution. The linewidth is orders of magnitudes smaller than that of the cavity as well as the inhomogeneous gain broadening and exhibits reduced sensitivity to cavity frequency noise.

scholarly journals Superradiant lasing in inhomogeneously broadened ensembles with spatially varying coupling

2021 ◽  
Vol 1 ◽  
pp. 73
Author(s):  
Anna Bychek ◽  
Christoph Hotter ◽  
David Plankensteiner ◽  
Helmut Ritsch
Keyword(s):  
Optical Pumping ◽  
Spectral Width ◽  
Stimulated Emission ◽  
Optical Clock ◽  
Frequency Noise ◽  
Atomic Coherence ◽  
Atom Number ◽  
Large Bandwidth ◽  
Large Numbers ◽  
Spatially Varying

Background: Theoretical studies of superradiant lasing on optical clock transitions predict a superb frequency accuracy and precision closely tied to the bare atomic linewidth. Such a superradiant laser is also robust against cavity fluctuations when the spectral width of the lasing mode is much larger than that of the atomic medium. Recent predictions suggest that this unique feature persists even for a hot and thus strongly broadened ensemble, provided the effective atom number is large enough. Methods: Here we use a second-order cumulant expansion approach to study the power, linewidth and lineshifts of such a superradiant laser as a function of the inhomogeneous width of the ensemble including variations of the spatial atom-field coupling within the resonator. Results: We present conditions on the atom numbers, the pump and coupling strengths required to reach the buildup of collective atomic coherence as well as scaling and limitations for the achievable laser linewidth. Conclusions: We show how sufficiently large numbers of atoms subject to strong optical pumping can induce synchronization of the atomic dipoles over a large bandwidth. This generates collective stimulated emission of light into the cavity mode leading to narrow-band laser emission at the average of the atomic frequency distribution. The linewidth is orders of magnitudes smaller than that of the cavity as well as the inhomogeneous gain broadening and exhibits reduced sensitivity to cavity frequency noise.

Atomic coherence effects within the sodium D1manifold. II. Coherent optical pumping

1994 ◽  
Vol 6 (4) ◽  
pp. 245-260 ◽  
Author(s):  
D E Nikonov ◽  
U W Rathe ◽  
M O Scully ◽  
Shi-Yao Zhu ◽  
E S Fry ◽  
...  
Keyword(s):  
Optical Pumping ◽  
Atomic Coherence ◽  
Coherence Effects

Stimulated emission in erbium-doped silicon structures under optical pumping

2001 ◽  
Vol 81 (1-3) ◽  
pp. 52-55 ◽  
Author(s):  
M.S. Bresler ◽  
O.B. Gusev ◽  
E.I. Terukov ◽  
I.N. Yassievich ◽  
B.P. Zakharchenya ◽  
...  
Keyword(s):  
Optical Pumping ◽  
Stimulated Emission ◽  
Erbium Doped ◽  
Doped Silicon ◽  
Silicon Structures

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.

CS Optical Pumping Magnetic Sensor Spectrum Lamp Drive Circuit Design Based on PI Feedback Controller

2014 ◽  
Vol 568-570 ◽  
pp. 473-477 ◽  
Author(s):  
Chao Tan ◽  
Li Fang ◽  
Xue Bai
Keyword(s):  
Emission Intensity ◽  
Optical Pumping ◽  
Spectral Width ◽  
Control Measures ◽  
Experimental Result ◽  
Crystal Oscillator ◽  
Optical Source ◽  
Optical Pump ◽  
Rf Power Amplifier ◽  
Drive Circuit

The optical source is one of the key components for the optical pump magnetic field sensor, its spectral width, stability and emission intensity directly related to the sensitivity of the sensor. The CS Spectral Lamp drive signal source was produced by crystal oscillator and amplified by the power controllable RF power amplifier. For achieving the aim of luminous intensity controllable and more stability, the reference controllable analog PI negative feedback control measures were used in the drive circuit. Contrast experimental result show that: the emission intensity of CS spectrum lamp is more stable and less affected by temperature if using the drive circuit which discussed in this paper.

scholarly journals Superradiance on the millihertz linewidth strontium clock transition

2016 ◽  
Vol 2 (10) ◽  
pp. e1601231 ◽  
Author(s):  
Matthew A. Norcia ◽  
Matthew N. Winchester ◽  
Julia R. K. Cline ◽  
James K. Thompson
Keyword(s):  
Cavity Mode ◽  
Optical Cavity ◽  
Atomic Clock ◽  
Laser Frequency ◽  
Gain Medium ◽  
Optical Clock ◽  
Frequency Noise ◽  
Clock Transition ◽  
Reference Cavity ◽  
High Finesse

Laser frequency noise contributes a significant limitation to today’s best atomic clocks. A proposed solution to this problem is to create a superradiant laser using an optical clock transition as its gain medium. This laser would act as an active atomic clock and would be highly immune to the fluctuations in reference cavity length that limit today’s best lasers. We demonstrate and characterize superradiant emission from the millihertz linewidth clock transition in an ensemble of laser-cooled 87Sr atoms trapped within a high-finesse optical cavity. We measure a collective enhancement of the emission rate into the cavity mode by a factor of more than 10,000 compared to independently radiating atoms. We also demonstrate a method for seeding superradiant emission and observe interference between two independent transitions lasing simultaneously. We use this interference to characterize the relative spectral properties of the two lasing subensembles.

Spontaneous and Stimulated Intersubband Emission Under Optical Pumping

1996 ◽  
Vol 450 ◽  
Author(s):  
P. Boucaud ◽  
S. Sauvage ◽  
O. Gauthier-Lafaye ◽  
Z. Moussa ◽  
F.-H. Julien ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Free Electron Laser ◽  
Population Inversion ◽  
Laser Emission ◽  
Optical Pumping ◽  
Stimulated Emission ◽  
Mid Infrared ◽  
Asymmetric Quantum ◽  
Waveguide Length ◽  
Subband Energy

ABSTRACTWe have investigated the mid-infrared spontaneous and stimulated emission between confined subbands in the conduction band of GaAs/AlGaAs quantum wells. The carriers which give rise to the intersubband emission are excited in the upper subbands using an intersubband optical pumping in coupled asymmetric quantum wells. The quantum wells are designed using phonon engineering in order to obtain population inversion between the second and first excited subband. This is obtained by adjusting the subband energy spacing between E2 and E1 close to the optical phonon energy which in turn allows an efficient relaxation. We have first observed intersubband spontaneous emission between E3 and E2 at 14 μm using an intersubband pumping with a CO2 laser in resonance with the E1-E3 transition. In a second set of experiments, the quantum wells are embedded in an infrared waveguide. We have measured the stimulated intersubband gain using a picosecond two-color free electron laser. The first color bleaches the E1-E3 transition and provides the population inversion. The intersubband stimulated gain is measured versus the waveguide length and photon energy. Stimulated gains ≈ 80 cm−1 are reported thus demonstrating that laser emission under optical pumping appears feasible in optimized structures. Finally, we show that intersubband emission can also be observed in quantum wells using an interband optical pumping.

scholarly journals Субмонослойные квантовые точки InGaAs/GaAs, выращенные методом МОС-гидридной эпитаксии

2019 ◽  
Vol 53 (8) ◽  
pp. 1159
Author(s):  
В.Я. Алешкин ◽  
Н.В. Байдусь ◽  
А.А. Дубинов ◽  
К.Е. Кудрявцев ◽  
С.М. Некоркин ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Room Temperature ◽  
Optical Pumping ◽  
Liquid Nitrogen Temperature ◽  
Stimulated Emission ◽  
Threshold Power ◽  
Gaas Substrates ◽  
Dot Density ◽  
Hydride Epitaxy

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.

scholarly journals Magnetooptical studies and stimulated emission in narrow gap HgTe/CdHgTe structures in the very long wavelength infrared range

2018 ◽  
Vol 52 (4) ◽  
pp. 464
Author(s):  
V.V. Rumyantsev ◽  
L.S. Bovkun ◽  
A.M. Kadykov ◽  
M.A. Fadeev ◽  
A.A. Dubinov ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Optical Pumping ◽  
High Energy ◽  
Stimulated Emission ◽  
Infrared Range ◽  
Recombination Mechanism ◽  
Carrier Heating ◽  
Long Wavelength ◽  
Carrier Recombination ◽  
Long Wavelength Infrared

AbstractWe investigate the prospects of HgTe/HgCdTe quantum wells for long-wavelength interband lasers (λ = 15–30 μm). The properties of stimulated emission (SE) and magnetoabsorbtion data of QWs structures with wide-gap HgCdTe dielectric waveguide provide an insight on dominating non-radiative carrier recombination mechanism. It is shown that the carrier heating under intense optical pumping is the main factor limiting the SE wavelength and intensity, since the Auger recombination is greatly enhanced when carriers populate high energy states in the valence band.

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