TY - JOUR

T1 - Relaxation Times and Population Inversion of Excited States of Arsenic Donors in Germanium

AU - Zhukavin, R. Kh

AU - Kovalevskii, K. A.

AU - Choporova, Yu Yu

AU - Tsyplenkov, V. V.

AU - Gerasimov, V. V.

AU - Bushuikin, P. A.

AU - Knyazev, B. A.

AU - Abrosimov, N. V.

AU - Pavlov, S. G.

AU - Hübers, H. W.

AU - Shastin, V. N.

N1 - Publisher Copyright: © 2019, Pleiades Publishing, Inc.

PY - 2019/11/1

Y1 - 2019/11/1

N2 - The relaxation times of excited states of arsenic dopant in germanium at cryogenic temperatures T < 15 K have been experimentally studied by the optical pump-probe method using radiation of a free-electron laser. Two variants of the excitation of impurity centers have been used in the experiment: (i) from the 1s(A1) ground state of the dopant and (ii) from the 1s(T2) first excited state having a finite thermal population. In the former variant, it has been shown that the decay times of the 2p0 and 3p± states are about 0.8 and 0.6 ns, respectively. In the latter variant, a single measurement can simultaneously provide the relaxation times of two 2p± and 1s(T2) states about 0.6 and no more than 0.16 ns, respectively. The data obtained have indicated the possibility of forming population inversion and the gain of terahertz radiation at the 2p± → 1s(T2) and 2p0 → 1s(T2) transitions at the optical excitation of the mentioned impurity centers.

AB - The relaxation times of excited states of arsenic dopant in germanium at cryogenic temperatures T < 15 K have been experimentally studied by the optical pump-probe method using radiation of a free-electron laser. Two variants of the excitation of impurity centers have been used in the experiment: (i) from the 1s(A1) ground state of the dopant and (ii) from the 1s(T2) first excited state having a finite thermal population. In the former variant, it has been shown that the decay times of the 2p0 and 3p± states are about 0.8 and 0.6 ns, respectively. In the latter variant, a single measurement can simultaneously provide the relaxation times of two 2p± and 1s(T2) states about 0.6 and no more than 0.16 ns, respectively. The data obtained have indicated the possibility of forming population inversion and the gain of terahertz radiation at the 2p± → 1s(T2) and 2p0 → 1s(T2) transitions at the optical excitation of the mentioned impurity centers.

KW - INTRACENTER RELAXATION

UR - http://www.scopus.com/inward/record.url?scp=85078329484&partnerID=8YFLogxK

U2 - 10.1134/S0021364019220144

DO - 10.1134/S0021364019220144

M3 - Article

AN - SCOPUS:85078329484

VL - 110

SP - 677

EP - 682

JO - JETP Letters

JF - JETP Letters

SN - 0021-3640

IS - 10

ER -