TY - JOUR
T1 - Effect of dephasing on modulation transfer in potassium
AU - Shukla, Vinay
AU - Chakraborty, Pratanu
AU - Ray, Ayan
N1 - Publisher Copyright:
© The Author(s) 2024.
PY - 2024/10
Y1 - 2024/10
N2 - In this work, experimental studies on the effect of dephasing on modulation transfer are reported. Here Potassium D1 transition, i.e., 39K 4S1/2(F) → 4P1/2(F/), is used as the medium. The 4 S→4P connection is modified by introducing two independent lasers. The separation between ground hyperfine states 4S1/2(F = 2,1) is almost half of Doppler width (~ 815 MHz). Hence, the two-level connections satisfied by respective lasers are overlapping in nature. In such cases, the existing optical pumping for particular F = 1, 2→ F/ channel influences each other. Further, the D1 transition itself is an open transition, i.e., it does not have any cyclic decay route. Hence, decay from each of the F/=2,1 states can also influence the population in the other F/state. Our pump-probe spectroscopy results clearly show the presence of Four Wave Mixing due to degenerate two-level and Vee (V) coupling, Electromagnetically Induced Transparency (EIT) signals due to single Lambda (Λ) and Double Λ connections. We have studied these signals as a function of dephasing, which is mainly contributed by transit time broadening for two different regimes of pump laser intensities: (i) below and (ii) above saturation intensity level of 4S1/2(F) → 4P1/2(F/) transition. The pump laser is current modulated, and phase-sensitive detection is performed on the probe transmission to study modulation transfer under different values of coherent dephasing. For this purpose, the beam size of the pump laser is varied systematically. This study provides a scope to explore the modulation transfer as a function of transit time broadening, and it may find applications in photonics technology where potassium vapor is used as a medium.
AB - In this work, experimental studies on the effect of dephasing on modulation transfer are reported. Here Potassium D1 transition, i.e., 39K 4S1/2(F) → 4P1/2(F/), is used as the medium. The 4 S→4P connection is modified by introducing two independent lasers. The separation between ground hyperfine states 4S1/2(F = 2,1) is almost half of Doppler width (~ 815 MHz). Hence, the two-level connections satisfied by respective lasers are overlapping in nature. In such cases, the existing optical pumping for particular F = 1, 2→ F/ channel influences each other. Further, the D1 transition itself is an open transition, i.e., it does not have any cyclic decay route. Hence, decay from each of the F/=2,1 states can also influence the population in the other F/state. Our pump-probe spectroscopy results clearly show the presence of Four Wave Mixing due to degenerate two-level and Vee (V) coupling, Electromagnetically Induced Transparency (EIT) signals due to single Lambda (Λ) and Double Λ connections. We have studied these signals as a function of dephasing, which is mainly contributed by transit time broadening for two different regimes of pump laser intensities: (i) below and (ii) above saturation intensity level of 4S1/2(F) → 4P1/2(F/) transition. The pump laser is current modulated, and phase-sensitive detection is performed on the probe transmission to study modulation transfer under different values of coherent dephasing. For this purpose, the beam size of the pump laser is varied systematically. This study provides a scope to explore the modulation transfer as a function of transit time broadening, and it may find applications in photonics technology where potassium vapor is used as a medium.
UR - http://www.scopus.com/inward/record.url?scp=85204281015&partnerID=8YFLogxK
U2 - 10.1007/s00340-024-08314-w
DO - 10.1007/s00340-024-08314-w
M3 - Article
AN - SCOPUS:85204281015
SN - 0946-2171
VL - 130
JO - Applied Physics B: Lasers and Optics
JF - Applied Physics B: Lasers and Optics
IS - 10
M1 - 180
ER -