https://doi.org/10.1007/s100530170259
Spectral linewidth of inversionless and Raman lasers in V-type three-level systems
Department of Physics, Huazhong Normal University, Wuhan 430079, P.R. China
Corresponding author: a xmhu@phy.ccnu.edu.cn
Received:
25
October
1999
Revised:
10
March
2000
Published online: 15 March 2001
A theoretical analysis of the spectral linewidth of V-type inversionless and
Raman lasers is presented. First, we examine the effects of the atomic
coherence between dressed states and the Autler-Townes splitting on the
linewidth. It is demonstrated that near above threshold, the V inversionless
laser has a narrower linewidth than that of the two-level laser. Instead of
the dressed coherence, it is the Autler-Townes splitting that is responsible
for the linewidth reduction though the dressed coherence determines the
laser gain. Next, we explore the effects of the generated laser intensity on
the linewidth. It is shown that the linewidths of the V inversionless and
Raman lasers follow the usual 1/I decrease for smaller laser intensity I,
but a slower decrease than 1/I for larger laser intensity. For the V
Raman laser, even more surprisingly, with the laser intensity increasing,
the linewidth appreciably increases as well. As a result, well above
threshold, the V inversionless and Raman lasers may have a larger linewidth
than that of the two-level laser. Finally, a comparison is made between the
V lasers and the lasers. It is found that the linewidth of the
inversionless laser shows a fast
decay under optimum
conditions.
PACS: 42.50.Lc – Quantum fluctuations, quantum noise, and quantum jumps / 42.50.Gy – Effects of atomic coherence on propagation, absorption, and amplification of light
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2001