Laser diode frequency stabilization with a fiber ring resonator

To improve the frequency stabilization of laser diode in the laser frequency scanned interferometric metrology, a modified method is proposed by using a fiber ring resonator. The theoretical analysis of this modified method is performed. Moreover, the Pound-Drever-Hall (PDH) technique is employed to obtain the frequency discrimination curve of a fiber ring resonator, whose finesse is 1260 and line-width is 270 kHz. The simulated results show that the curve has a steep slope near the resonant frequency, which proves the sensitivity of this system to the frequency deviation, so the modified method has great potential for the frequency stabilization of a laser diode.     

Frequency stabilization in FBG external cavity semiconductor laser based on acetylene absorption method

A frequency-stabilized 1.53 μm FBG external-cavity semiconductor laser by using acetylene absorption is presented and its basic principles are introduced. Graded refractive index fiber and pigtailed fiber are used in the absorption air chamber to enhance the coupling stability. The impact of the background power is eliminated by using the third-harmonic mode-locking technique. A lock-in amplifier is utilized to ensure that the output laser wavelength is locked at the C2H2 absorption line of 1530.37 nm. The frequency stability reaches 10^-8 within 24 h.     

Frequency stabilization in FBG external cavity semiconductor laser based on acetylene absorption method

A frequency-stabilized 1.53 μm FBG external-cavity semiconductor laser by using acetylene absorption is presented and its basic principles are introduced. Graded refractive index fiber and pigtailed fiber are used in the absorption air chamber to enhance the coupling stability. The impact of the background power is eliminated by using the third-harmonic mode-locking technique. A lock-in amplifier is utilized to ensure that the output laser wavelength is locked at the C2H2 absorption line of 1530.37 nm. The frequency stability reaches 10-8 within 24 h.     

一种适合于同轴放电气体激光器的多程环形腔

本文提出了一种适用于同轴放电气体激光器的环形腔方案,给出了这种腔的设计和光束特性。     

Frequency stabilization of an external cavity laser diode usingelectrooptic effect

An external cavity laser diode, which consists of a LiNbO₃ phase modulator, was frequency-stabilized to a resonance frequency of a Fabry-Perot interferometer using the electrooptic effect. The optical frequency fluctuation was detected through a Fabry-Perot interferometer and the detected signal was negatively fed back to the phase modulator to reduce the frequency fluctuation. The rear facet of the electrooptic phase modulator was coated with gold and used as an external mirror. At feedback-off state, the peak-to-peak frequency fluctuation of the laser diode was 52 MHz in 2 min. At feedback-on state, the peak-to-peak frequency fluctuation was reduced to 1.5 MHz. This condition was maintained for the duration of the observation, 1 h and 40 min     

Simulations of a ring resonator free-electron laser

A relatively high gain (≈25 to 40%) free-electron laser (FEL) with an optical ring resonator is simulated using the code FELEX. The laser system corresponds to the `burst mode' FEL. The ring consists of paraboloids, grazing incidence hyperboloids, and a grating rhomb. The wiggler is 5 m in length and has an adjustable taper, while the electron beam is produced by an RF linac. The optical elements of the ring together with the FEL interaction in the wiggler are modeled in three spatial dimensions to investigate the system from start-up to saturation. Both single-frequency and finite-pulse simulations are performed     

用改变激光等离子体折射率的方法稳定He-Ne激光器的频率

本文介绍一种Zeeman He-Ne气体激光器新的稳频方法,通过控制激光等离子体介质的折射率来稳定激光器的频率。系统使用普通单模He-Ne激光管,不需要特殊加工的、带压电陶瓷(PZT)的稳频激光管。由于采用了锁相技术,它的自差拍频率的变化率小于1Hz,其光频的稳定度为2.2×10~(-11)(取样时间τ=10s)。两个月内,频率再现性为2×10~(-8)。频率锁定点可在大于200MHz的范围内连续调谐。     

A tunable dual-wavelength erbium-doped fiber ring laser using a self-seeded Fabry-Perot laser diode

A tunable dual-wavelength erbium-doped fiber ring laser using a self-seeded Fabry-Perot laser diode (FP-LD) is proposed and demonstrated. By adding an FP-LD incorporated with a tunable bandpass filter within the ring cavity, the fiber laser can lase two wavelengths simultaneously because of the self-seeded mechanism. This dual-wavelength output exhibits a good performance having the optical side-mode suppression ratio over 31 dB. The wavelength-tuning range of this tunable dual-wavelength fiber laser can be up to 9 nm.     

Frequency stabilization of a traveling-wave semiconductor ringlaser using a fiber resonator as a frequency reference

A fiber resonator with a temperature drift rate of better than 5×10^-4° C/hour is used for controlling the frequency stability of a 1.3 μm wavelength external cavity semiconductor ring laser. A frequency stability of about 600 KHz/hour is achieved     

Tests of a grazing-incidence ring resonator free-electron laser

The authors describe operational experience of the first free-electron laser (FEL) using a grazing-incidence ring resonator. The Boeing FEL optical cavity was changed from a simple concentric cavity using two spherical mirrors to a larger grazing-incidence ring resonator. Initial tests showed that poorly positioned ring focus and unreliable pointing alignment resulted in reduced and structured FEL output. Later efforts concentrated on improving the resonator alignment techniques and lowering the single-pass losses. FEL performance and reliability have significantly improved due to better ring alignment. The alignment procedure and recent lasing results are described. The effect the electron beam has on lasing is also discussed. Measurements are presented showing FEL temporal output and wavelength are sensitive to electron beam energy variation     

480nm激光器的双光子DAVLL谱稳频

480nm激光的稳频对于实现铷原子从基态双光子相干激发到里德堡态必不可少。本工作基于梯形构型下的电磁诱导透明现象,一种新的480nm激光器稳频技术采用偏振谱稳频的780nm激光作为探测光而480nm激光则作为耦合光,在外加偏置磁场作用下产生的双光子双色原子气体激光锁频（DAVLL）谱方法,将该谱信号通过比例-积分-微分电路后反馈回480nm激光器即可实现稳频。在频率锁定后,480nm激光器和780nm激光器长时间稳频的总线宽为1MHz左右。     

激光二极管部分端面泵浦混合腔板条激光器研究进展

激光二极管分端面泵浦混合腔板条激光器(Innoslab laser)是上世纪九十年代后期在德国发展起来的一种新型全固态激光技术。介绍了这一技术的基本结构和优点,其发展过程中的一些重要研究工作,以及国内外研究现状,并对下一步的发展进行了展望。     

Frequency stabilization of gas lasers

The state of the art in the field of frequency stabilization of gas lasers is surveyed. A brief discussion of the methods employed to determine the frequency stability of lasers is followed by a listing of the principle causes of frequency instability. The close relationship existing between the control system design and the laser environment is pointed out. Stabilization techniques based on the use of atomic resonance and on the use of interferometers are discussed in detail. Many of these techniques are capable of achieving long-term frequency stabilities of one part in 10⁹or better, which appears to be entirely adequate for most systems applications.     

基于调节转移技术稳定激光二极管的频率

阐述了利用调节及转换技术稳定激光二极管发射器的频率 ,这种发射器可以发射纳米波长的激光。通过分析两个相互独立的激光器系统中存在的振动信号 ,知道该振动信号已揭示了在 0 .0 9秒的时间内有 10 - 1 1 秒的时间频率是相对稳定的 ,并且在 1秒的时间内似乎可以得到 10 - 1 2 的最低干扰频率。为避免产生共振 ,充分吸收铯元素的D2 线作为频率参考及非线性光谱研究     

Frequency stability and stabilization of a chemical laser

We have built a low-power CW HF/DF chemical laser, designed to achieve high-frequency stability. Measurements are reported which characterize the instantaneous spectral width of the laser output to less than one part in 10¹¹(Deltanu < 1kHz) and the variations in absolute frequency of this emission with time to four parts in 10¹⁰(Deltanu = pm20kHz) per 0.1 ms. Two experiments to actively stabilize the laser frequency are reported. In one experiment the laser was locked to a high-finesse Fabry-Perot to five parts in 10⁹(Deltanu = pm250kHz) for many minutes. In the other experiment one laser was locked to another using heterodyne beat spectroscopy to 1.7 parts in 10⁹(Deltanu = pm85kHz). The stabilization experiments were limited by the feedback loops used.     

Resonant-tunnelling diode oscillator using a slot-coupled quasioptical open resonator

A resonant-tunnelling diode has oscillated at X-band frequencies in a microwave circuit consisting of a slot antenna coupled to a semiconfocal open resonator. Coupling between the open resonator and the slot oscillator improves the noise-to-carrier ratio by about 36 dB relative to that of the slot oscillator alone in the 100-200 kHz range. A circuit operating near 10 GHz has been designed as a scale model for millimetre- and submillimetre-wave applications.<>     

Frequency characteristics of self-sustained intensity oscillation of a laser diode using a delayed electrical feedback

Frequency characteristics of self-sustained intensity oscillation of a laser diode, introduced by a delayed electrical feedback using an optical fiber, is investigated. A step-index multimode fiber is utilized as an optical delay line, and it is found that the spectral profile of the self-sustained intensity oscillation follows the baseband frequency response of the fiber.