Open AccessIntensity noise of tunable infrared laser based on singly resonant optical parametric oscillator
Author(s) -
Dandan Nie,
Jing Feng,
Meng Qi,
Yuanji Li,
Kuanshou Zhang
Publication year - 2020
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.69.20191952
Subject(s) - materials science , fabry–pérot interferometer , optics , optical parametric oscillator , laser , resonator , infrared , optoelectronics , crystal (programming language) , lithium niobate , physics , computer science , programming language
The infrared laser sources have important applications in many fields such as real-time detection, gas sensing or tracing, high-resolution spectral analysis and quantum optics. In this paper, we develop an infrared laser source with mode-hop-free broadband tunability by using a singly optical parametric oscillator (SRO) based on the magnesium-oxide doped periodically poled lithium niobite (MgO:PPLN) crystal. A polished lithium niobite crystal with a thickness of 1 mm is used as an etalon that is inserted into the cavity of SRO to realize continuous mode-hop-free tuning. The resonant signal in SRO is frequency stabilized to the transmission peak of intracavity etalon. Owing to the high stability of the resonator, continuous mode-hop-free tuning with a bandwidth of 2063.7 GHz for both signal and idler is realized. The oscillation threshold of SRO is 7.3 W. The signal of 4.3 W over 1551.91568.6 nm and idler of 2.1 W over 3307.33384.3 nm are generated for 22 W of pump power by tuning the temperature of the crystal from 20 ℃ to 70 ℃. The slope efficiency of 42.6% and optical conversion efficiency of 29% are obtained. Then the intensity noise characteristics of generated infrared laser are further studied theoretically and experimentally. The fluctuation characteristics of the SRO emission can be computed just by using a semiclassical approach. We analyze theoretically the factors that affect the intensity noise of the signal and idler. The temperature of the MgO:PPLN crystal and the modulation frequency of the etalon are important parameters, which can affect the intensity noise characteristics of signal and idler laser. Therefore, we investigate experimentally the variation of the intensity noise characteristics by changing the temperature of the crystal and the modulation frequency of the etalon. The intensity noise of the signal and idler laser are optimized through controlling the temperature in a range of 2060 ℃ and the modulation frequency ranging from 2 kHz to 8 kHz, respectively. The experimental data basically accord with the theoretical calculations. When the operating temperature of the MgO:PPLN crystal is controlled at 60 ℃ and the modulation frequency of the etalon is 8 kHz, the intensity noise of the signal and the idler laser are reduced by 11 dB and 8 dB, respectively. The optimized infrared laser can provide a high-quality laser source for subsequent quantum optics research.