Polarization of luminescence spectra and electron-hole plasma radiation in GaSe single crystals at high level of excitation

Baltramiejūnas, R.; Narkevičius, V.; Skaistys, E.; Vaitkus, J.; Viščakas, J.

doi:10.1007/bf02723537

“…14,15 In particular, gain and stimulated emission measurements in these materials have been performed by different authors and several hypotheses have been argued to explain the nature of the stimulated emissions at room and low temperatures. [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] Many of these studies (performed during the latest 40 years) failed in correlating the unusual electronic properties of these compounds and the electronic band structure obtained from theoretical calculations. The main reason for the failure was the lack of detailed knowledge of the electronic band structure near the fundamental band gap.…”

Section: Introductionmentioning

confidence: 99%

Band structure of indium selenide investigated by intrinsic photoluminescence under high pressure

Manjón

¹

,

Segura

²

,

Muñoz‐Sanjosé

³

et al. 2004

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This paper reports on photoluminescence experiments in n-type indium selenide ͑T = 300 K͒ under hydrostatic pressure up to 7 GPa at low and high excitation densities. Photoluminescence measurements at low excitation density exhibit a broad band around the energy of the direct band gap of InSe and with the same pressure dependence. The reversible increase of its linewidth above 1 GPa is associated to a direct-to-indirect band-gap crossover between valence band maxima. The reversible decrease of its intensity above 4 GPa is interpreted as evidence of a direct-to-indirect band-gap crossover between conduction band minima. Photoluminescence measurements under high excitation density exhibit several spontaneous and stimulated emission bands. The different components of these bands can be attributed to radiative emission from different minima of the conduction band to different maxima of the valence band in the framework of the band-gap renormalization theory in a multivalley scenario. The image of the electronic band structure of InSe provided by these measurements agrees with the previous analysis of the optical absorption coefficient of InSe and In 1−x Ga x Se.

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“…The detection and investigation of thermal nonlinearity in GaSe crystals is of particular interest. Previously, optical nonlinearities of electronic origin were discovered in GaSe, such as harmonic generation [1,2], parametric light generation [3,4], electron-hole plasma [5][6][7][8][9], stimulated emission [10][11][12][13][14], multiphoton absorption [ 15,16], etc., have been observed in these crystals.…”

Section: Introductionmentioning

confidence: 99%

Untitled

2021

CL

0

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The nonlinear light absorption at the fundamental absorption edge under laser excitation in GaSe crystals has been investiqated experimentally. It is shown that at high excitation levels, the absorption coefficient shifted towards lower energies (red shift). The nonlinear refractive index is positive at frequencies below the absorption edge and negative on the high-energy side. The laser-induced negative index change is referred to as a selfdefocusing optical nonlinearity. The positive Δn(ω) on the high-energy side to a selffocusing optical nonlinearity. The measured parameters showed that GaSe crystals exhibits strong nonlinear properties.

show abstract

“…The detection and investigation of thermal nonlinearity in GaSe crystals is of particular interest. Previously, optical nonlinearities of electronic origin were discovered in GaSe, such as harmonic generation [1,2], parametric light generation [3,4], electron-hole plasma [5][6][7][8][9], stimulated emission [10][11][12][13][14], multiphoton absorption [ 15,16], etc., have been observed in these crystals.…”

Section: Introductionmentioning

confidence: 99%

Thermal nonlinearities in GaSe

Salmanov¹,

Jafarova²,

Guseinova³

et al. 2021

CL

2

0

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The nonlinear light absorption at the fundamental absorption edge under laser excitation in GaSe crystals has been investiqated experimentally. It is shown that at high excitation levels, the absorption coefficient shifted towards lower energies (red shift). The nonlinear refractive index is positive at frequencies below the absorption edge and negative on the high-energy side. The laser-induced negative index change is referred to as a selfdefocusing optical nonlinearity. The positive Δn(ω) on the high-energy side to a selffocusing optical nonlinearity. The measured parameters showed that GaSe crystals exhibits strong nonlinear properties.

show abstract

Polarization of luminescence spectra and electron-hole plasma radiation in GaSe single crystals at high level of excitation

Cited by 16 publications

References 5 publications

Band structure of indium selenide investigated by intrinsic photoluminescence under high pressure

Band structure of indium selenide investigated by intrinsic photoluminescence under high pressure

Untitled

Thermal nonlinearities in GaSe

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