An experimental investigation was made of fluctuations of the spectral distribution of the intensity in the wide-band spectrum of a ring cw traveling-wave dye laser. Allowance for the averaging within the limits of the instrumental function of a spectrometer was made by analyzing the noise power spectra obtained for the recorded intensity distributions. A good agreement with the theory was observed. The threshold of detection of an intracavity spectrometer, denned in terms of the absorption coefficient, was found to be governed by the quantum nature of the radiation used in the spectrometer and amounted to ~ 3 X 10 − 17 cm − 1 when the accumulation time was 20 s.An experimental investigation was made of fluctuations of the spectral distribution of the intensity in the wide-band spectrum of a ring cw traveling-wave dye laser. Allowance for the averaging within the limits of the instrumental function of a spectrometer was made by analyzing the noise power spectra obtained for the recorded intensity distributions. A good agreement with the theory was observed. The threshold of detection of an intracavity spectrometer, denned in terms of the absorption coefficient, was found to be governed by the quantum nature of the radiation used in the spectrometer and amounted to ~ 3 X 10 − 17 cm − 1 when the accumulation time was 20 s.

Soviet Journal of Quantum ElectronicsJan 31, 198917 citations

Loss of spectral memory in the relaxation oscillations of a multimode solid-state laser

D. Romanini, Alexander A. Kachanov, Éric Lacot +1 more

To test the application of solid-state lasers to intracavity laser absorption spectroscopy (ICLAS), we studied a neodymium-doped glass laser, in the presence of extreme relaxation oscillations (up to ${10}^{8}$ intensity contrast). The contrast of these oscillations could be varied by changing the Q-switch transition time. The recorded absorption spectra accurately follow the regular ICLAS behavior except when the intensity in the first relaxation oscillation minimum becomes too low. In such a case, we find that the ICLAS absorption spectrum accumulated during the first spike is ``forgotten'' by the system. Numerical simulations were done which accurately describe the observed transition to a regime of memory loss, when the number of photons circulating in each mode drops close to 1. These simulations show that the mechanism of memory loss is the prevailing of spontaneous over stimulated emission. This effect sets the fundamental limit of the sensitivity of an ICLAS spectrometer where the nonlinear mode interactions are negligible. This effect was observed before only in a diode laser system with high internal losses. In this paper we report an observation of ICLAS sensitivity saturation by spontaneous emission during relaxation oscillations in a laser with low cavity losses. \textcopyright{} 1996 The American Physical Society.To test the application of solid-state lasers to intracavity laser absorption spectroscopy (ICLAS), we studied a neodymium-doped glass laser, in the presence of extreme relaxation oscillations (up to ${10}^{8}$ intensity contrast). The contrast of these oscillations could be varied by changing the Q-switch transition time. The recorded absorption spectra accurately follow the regular ICLAS behavior except when the intensity in the first relaxation oscillation minimum becomes too low. In such a case, we find that the ICLAS absorption spectrum accumulated during the first spike is ``forgotten'' by the system. Numerical simulations were done which accurately describe the observed transition to a regime of memory loss, when the number of photons circulating in each mode drops close to 1. These simulations show that the mechanism of memory loss is the prevailing of spontaneous over stimulated emission. This effect sets the fundamental limit of the sensitivity of an ICLAS spectrometer where the nonlinear mode interactions are negligible. This effect was observed before only in a diode laser system with high internal losses. In this paper we report an observation of ICLAS sensitivity saturation by spontaneous emission during relaxation oscillations in a laser with low cavity losses. \textcopyright{} 1996 The American Physical Society.

Physical Review AJul 1, 19968 citations

Detection of spectrally narrow light emission by laser intra-cavity spectroscopy

Valery M. Baev, Klaus J. Boller, A. Weiler +1 more

Optics CommunicationsJun 1, 198710 citations

A dye laser spectrometer for high resolution spectroscopy

J. Dirscherl, B. Neizert, T. Wegener +1 more

Optics CommunicationsJul 1, 199223 citations

To test the application of solid-state lasers to intracavity laser absorption spectroscopy (ICLAS), we studied a neodymium-doped glass laser, in the presence of extreme relaxation oscillations (up to

{10}^{8}

intensity contrast). The contrast of these oscillations could be varied by changing the Q-switch transition time. The recorded absorption spectra accurately follow the regular ICLAS behavior except when the intensity in the first relaxation oscillation minimum becomes too low. In such a case, we find that the ICLAS absorption spectrum accumulated during the first spike is ``forgotten'' by the system. Numerical simulations were done which accurately describe the observed transition to a regime of memory loss, when the number of photons circulating in each mode drops close to 1. These simulations show that the mechanism of memory loss is the prevailing of spontaneous over stimulated emission. This effect sets the fundamental limit of the sensitivity of an ICLAS spectrometer where the nonlinear mode interactions are negligible. This effect was observed before only in a diode laser system with high internal losses. In this paper we report an observation of ICLAS sensitivity saturation by spontaneous emission during relaxation oscillations in a laser with low cavity losses. \textcopyright{} 1996 The American Physical Society.