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中红外波段缺乏窄线宽、可精确调谐的激光源, 限制了中红外精密光谱的发展. 本文介绍了一种结合强光学反馈和光学锁相环技术的量子级联激光器(QCL)频率控制技术, 通过强光学反馈先抑制QCL频率噪声中的高频成分, 再使用光学锁相环将激光频率偏频锁定到另外一个超稳中红外激光源上. 通过相位超前电路拓展锁定带宽, 系统锁定后, 将功率谱中心窄拍频信号提高66 dBm, 低频区域相位噪声抑制到–81 dBc/Hz@2 kHz, 高频区域相位噪声抑制到101 dBc/Hz@2 MHz, 激光器线宽从3.8 MHz被压窄到3 Hz. 最终, 利用该激光器进行腔衰荡光谱信号的测量, 相较于未锁定激光, 信号的信噪比提升了5倍.The mid-infrared (MIR) spectral region, which corresponds to molecular vibrational and rotational energy level transitions, contains a wealth of molecular energy level information. By employing techniques such as cavity ring-down spectroscopy (CRDS), the MIR spectra can be precisely measured, thereby validating fundamental physical laws, the inversion of fundamental physical constants, and the detection of trace gases. However, technical noise from temperature fluctuations, mechanical vibrations, and current noise causes free-running quantum cascade laser (QCL) to suffer high-frequency noise, typically broadening the linewidth to the MHz range, thus reducing spectral resolution. Moreover, long-term drift in the laser frequency due to temperature and current fluctuations hinders high-precision spectroscopy, particularly for narrow-linewidth nonlinear spectroscopy, such as saturated absorption and multiphoton absorption spectroscopy. This work presents a method of combining optical feedback with an optical phase-locked loop (OPLL) for offset frequency locking, aiming to generate a mid-infrared (MIR) laser with excellent frequency characteristics. Strong optical feedback is employed to narrow the linewidth of the quantum cascade laser (QCL) acting as a slave laser, thereby alleviating the challenges associated with phase locking. The OPLL uses frequency-offset to lock the slave laser to the ultra-narrow laser. By adjusting the offset frequency, fine control of the slave laser is achieved. To ensure tight phase locking, the OPLL is based on the ADF4007, and combines a phase lead circuit to compensate for phase lag, effectively expanding the loop bandwidth of the system. In this work, the fundamental principles of the optical phase-locked loop are theoretically analyzed, and a basic model is established. The influence of loop bandwidth on locking performance is also investigated. Upon achieving phase locking using the combined optical feedback and OPLL system, the magnitude of the beat note of the two lasers is improved by 66 dBm, with phase noise suppressed to –81 dBc/Hz@2 kHz in the low-frequency region and -101 dBc/Hz@2MHz in the high-frequency region. The frequency noise power spectral density of both the master laser and slave laser is obtained via the error signal in the closed-loop system. Significant suppression of frequency noise is observed for the slave laser across both low- and high-frequency region, with suppression ratio reaching 86 dB at 100 Hz and 55 dB at 400 kHz. The frequency noise of the slave laser in the low-frequency domain is found to be comparable to that of the master laser. Based on the white noise response region in the frequency noise spectrum (from 200 Hz to 400 kHz), the locked slave laser linewidth is determined to be approximately 3 Hz, narrowing the initial MHz-level linewidth to match the Hz-level linewidth of the master laser. Finally, the locked laser is used to conduct cavity ring-down spectroscopy, achieving an improvement factor of 5 in the signal-to-noise ratio of the ringdown signal. This frequency-stabilized laser will be applied to high-precision spectroscopy for detecting radiocarbon isotopes in future.
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Keywords:
- quantum cascade laser /
- optical phase-locked loops /
- optical feedback
[1] Faist J, Capasso F, Sivco D L, Sirtori C, Hutchinson A L, Cho A Y 1994 Science 264 553
Google Scholar
[2] Yao Y, Hoffman A J, Gmachl C F 2012 Nat. Photonics 6 432
Google Scholar
[3] Hvozdara L, Pennington N, Kraft M, Karlowatz M, Mizaikoff B 2002 Vib. Spectrosc. 30 53
Google Scholar
[4] Bartalini S, Borri S, Cancio P, Castrillo A, Galli I, Giusfredi G, Mazzotti D, Gianfrani L, De Natale P 2010 Phys. Rev. Lett. 104 083904
Google Scholar
[5] Bartalini S, Borri S, Galli I, Giusfredi G, Mazzotti D, Edamura T, Akikusa N, Yamanishi M, De Natale P 2011 Opt. Express 19 17996
Google Scholar
[6] Genov G, Lellinger T E, Halfmann T, Peters T 2017 J. Opt. Soc. Am. B 34 2018
Google Scholar
[7] Drever R W P, Hall J L, Kowalski F V, Hough J, Ford G M, Munley A J, Ward H 1983 Appl. Phys. B 31 97
Google Scholar
[8] Pound R V 1946 Rev. Sci. Instum. 17 490
Google Scholar
[9] Black E D 2001 Am. J. Phys. 69 79
Google Scholar
[10] Zhao G, Tian J F, Hodges J T, Fleisher A J 2021 Opt. Lett. 46 3057
Google Scholar
[11] Fasci E, Coluccelli N, Cassinerio M, Gambetta A, Hilico L, Gianfrani L, Laporta P, Castrillo A, Galzerano G 2014 Opt. Lett. 39 4946
Google Scholar
[12] Maisons G, Carbajo P G, Carras M, Romanini D 2010 Opt. Lett. 35 3607
Google Scholar
[13] Remillard J, Uy D, Weber W, Capasso F, Gmachl C, Hutchinson A, Sivco D, Baillargeon J, Cho A 2000 Opt. Express 7 243
Google Scholar
[14] 杨家齐, 赵刚, 焦康, 高健, 闫晓娟, 赵延霆, 马维光, 贾锁堂 2024 物理学报 73 014205
Google Scholar
Yang J Q, Zhao G, Jiao K, Gao J, Yan X J, Zhao Y T, Ma W G, Jia S T 2024 Acta Phys. Sin. 73 014205
Google Scholar
[15] Bordonalli A C, Walton C, Seeds A J 1999 J. Light. Technol. 17 328
Google Scholar
[16] Satyan N, Liang W, Yariv A 2009 IEEE J. Quantum Electron. 45 755
Google Scholar
[17] Steed R J, Pozzi F, Fice M J, Renaud C C, Rogers D C, Lealman I F, Moodie D G, Cannard P J, Lynch C, Johnston L, Robertson M J, Cronin R, Pavlovic L, Naglic L, Vidmar M, Seeds A J 2011 Opt. Express 19 20048
Google Scholar
[18] 王建, 陈迪俊, 蔡海文, 冯俊波, 郭进 2018 中国激光 45 0401001
Google Scholar
Wang J, Chen D J, Cai H W, Feng J B, Guo J 2018 Chin. J. Lasers 45 0401001
Google Scholar
[19] Wang F D, Ma W X, Mei F, Ji Z H, Su D Q, Zhao Y T, Xiao L T, Jia S T 2023 Appl. Opt. 62 7169
Google Scholar
[20] Qin J, Zhou Q, Xie W L, Xu Y, Yu S G, Liu Z W Y, Tong Y T, Dong Y, Hu W S 2015 Opt. Lett. 40 4500
Google Scholar
[21] Satyan N, Vasilyev A, Liang W, Rakuljic G, Yariv A 2009 Opt. Lett. 34 3256
Google Scholar
[22] Zhao B B, Wang X G, Wang C 2020 ACS Photonics 7 1255
Google Scholar
[23] Lang R, Kobayashi K 1980 IEEE J. Quantum Electron. 16 347
Google Scholar
[24] Wang X G, Zhao B B, Grillot F, Wang C 2020 J. Appl. Phys. 127 073104
Google Scholar
[25] Domenico G D, Schilt S, Thomann P 2010 Appl. Opt. 49 4801
Google Scholar
[26] Fox R W, Oates C W, Hollberg L W 2003 Experimental Methods in the Physical Sciences (Vol. 40) (Amsterdam: Academic Press) pp1–46
[27] Kikuchi K 2012 Opt. Express 20 5291
Google Scholar
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图 4 (a)锁相环电路; (b)无源相位超前电路传递函数
Fig. 4. (a) Phase-locked loop circuit; (b) transfer function of the passive phase lead circuit.
图 6 (a)不同锁定拍频功率谱; (b)拍频中心1 kHz范围功率谱
Fig. 6. (a) Power spectral of beat frequencies under different conditions; (b) power spectral in the 1 kHz range at the center of beat frequencies.
图 8 主、从激光器频率噪声功率谱密度
Fig. 8. Power spectral density of frequency noise of the master and slave laser.
图 9 (a)未锁定透射腔模; (b)锁定透射腔模
Fig. 9. (a) Transmission cavity mode without locking; (b) transmission cavity mode without and with locking.
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[1] Faist J, Capasso F, Sivco D L, Sirtori C, Hutchinson A L, Cho A Y 1994 Science 264 553
Google Scholar
[2] Yao Y, Hoffman A J, Gmachl C F 2012 Nat. Photonics 6 432
Google Scholar
[3] Hvozdara L, Pennington N, Kraft M, Karlowatz M, Mizaikoff B 2002 Vib. Spectrosc. 30 53
Google Scholar
[4] Bartalini S, Borri S, Cancio P, Castrillo A, Galli I, Giusfredi G, Mazzotti D, Gianfrani L, De Natale P 2010 Phys. Rev. Lett. 104 083904
Google Scholar
[5] Bartalini S, Borri S, Galli I, Giusfredi G, Mazzotti D, Edamura T, Akikusa N, Yamanishi M, De Natale P 2011 Opt. Express 19 17996
Google Scholar
[6] Genov G, Lellinger T E, Halfmann T, Peters T 2017 J. Opt. Soc. Am. B 34 2018
Google Scholar
[7] Drever R W P, Hall J L, Kowalski F V, Hough J, Ford G M, Munley A J, Ward H 1983 Appl. Phys. B 31 97
Google Scholar
[8] Pound R V 1946 Rev. Sci. Instum. 17 490
Google Scholar
[9] Black E D 2001 Am. J. Phys. 69 79
Google Scholar
[10] Zhao G, Tian J F, Hodges J T, Fleisher A J 2021 Opt. Lett. 46 3057
Google Scholar
[11] Fasci E, Coluccelli N, Cassinerio M, Gambetta A, Hilico L, Gianfrani L, Laporta P, Castrillo A, Galzerano G 2014 Opt. Lett. 39 4946
Google Scholar
[12] Maisons G, Carbajo P G, Carras M, Romanini D 2010 Opt. Lett. 35 3607
Google Scholar
[13] Remillard J, Uy D, Weber W, Capasso F, Gmachl C, Hutchinson A, Sivco D, Baillargeon J, Cho A 2000 Opt. Express 7 243
Google Scholar
[14] 杨家齐, 赵刚, 焦康, 高健, 闫晓娟, 赵延霆, 马维光, 贾锁堂 2024 物理学报 73 014205
Google Scholar
Yang J Q, Zhao G, Jiao K, Gao J, Yan X J, Zhao Y T, Ma W G, Jia S T 2024 Acta Phys. Sin. 73 014205
Google Scholar
[15] Bordonalli A C, Walton C, Seeds A J 1999 J. Light. Technol. 17 328
Google Scholar
[16] Satyan N, Liang W, Yariv A 2009 IEEE J. Quantum Electron. 45 755
Google Scholar
[17] Steed R J, Pozzi F, Fice M J, Renaud C C, Rogers D C, Lealman I F, Moodie D G, Cannard P J, Lynch C, Johnston L, Robertson M J, Cronin R, Pavlovic L, Naglic L, Vidmar M, Seeds A J 2011 Opt. Express 19 20048
Google Scholar
[18] 王建, 陈迪俊, 蔡海文, 冯俊波, 郭进 2018 中国激光 45 0401001
Google Scholar
Wang J, Chen D J, Cai H W, Feng J B, Guo J 2018 Chin. J. Lasers 45 0401001
Google Scholar
[19] Wang F D, Ma W X, Mei F, Ji Z H, Su D Q, Zhao Y T, Xiao L T, Jia S T 2023 Appl. Opt. 62 7169
Google Scholar
[20] Qin J, Zhou Q, Xie W L, Xu Y, Yu S G, Liu Z W Y, Tong Y T, Dong Y, Hu W S 2015 Opt. Lett. 40 4500
Google Scholar
[21] Satyan N, Vasilyev A, Liang W, Rakuljic G, Yariv A 2009 Opt. Lett. 34 3256
Google Scholar
[22] Zhao B B, Wang X G, Wang C 2020 ACS Photonics 7 1255
Google Scholar
[23] Lang R, Kobayashi K 1980 IEEE J. Quantum Electron. 16 347
Google Scholar
[24] Wang X G, Zhao B B, Grillot F, Wang C 2020 J. Appl. Phys. 127 073104
Google Scholar
[25] Domenico G D, Schilt S, Thomann P 2010 Appl. Opt. 49 4801
Google Scholar
[26] Fox R W, Oates C W, Hollberg L W 2003 Experimental Methods in the Physical Sciences (Vol. 40) (Amsterdam: Academic Press) pp1–46
[27] Kikuchi K 2012 Opt. Express 20 5291
Google Scholar
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