The interaction between single-mode laser radiation and sodium vapour in a Fabry-Perot etalon and a ring optical cavity

The observation of optical bistability in the D lines of sodium vapour contained in both a Fabry-Perot etalon and a ring cavity is reported. As well, an enhanced transmission feature which appears under appropriate conditions in the Fabry-Perot etalon only is presented. This feature is interpreted in terms of a non-absorption resonance in an inverted V three-level model of the sodium D transitions.     

Confocal Fabry-Perot interferometer for frequency stabilization of laser

The frequency shift of laser source of Doppler lidar is required in the range of a few megahertzs. To satisfy this demand, a confocal Fabry-Perot (F-P) interferometer was manufactured as the frequency standard for frequency stabilization. After analyzing and contrasting the center frequency shift of confocal Fabry-Perot interferometers that are made of three different types of material with the change of temperature, the zerodur material was selected to fabricate the interferometer, and the cavity mirrors were optically contacted onto the end of spacer. The confocal Fabry-Perot interferometer was situated within a double-walled chamber, and the change of temperature in the chamber was less than 0.01 K. The experimental results indicate that the free spectral range is 500 MHz, the full-width at half maximum is 3.33 MHz, and the finesse is 150.     

Intracavity frequency doubling of a diode-pumped 946-nm Nd:YAG laser with bulk periodically poled MgO LiNbO(3)

We report what we believe is the first cw quasi-phase-matched intracavity frequency doubling of a diode-pumped 946-nm Nd:YAG laser by use of bulk periodically poled MgO-LiNbO(3). A maximum second-harmonic power of 5.9 mW was obtained at a laser diode power of 500 mW. The blue beam profile showed a TEM(00) single spatial mode of low ellipticity (1:1) because there was no walk-off problem. Bulk periodic domain inversion was accomplished by a corona discharge method with a first-order modulation period of 4.75 microm for a wavelength of 946 nm over a 2-mm interaction length in Z-cut 0.4-mm-thick MgO-LiNbO(3).     

High-power and high-efficiency operation of an all-solid-state,quasi-continuous-wave,titanium sapphire laser system

High-power and high-efficiency operation of an all-solid-state, quasi-continuous-wave, titanium sapphire laser is obtained with a diode-laser-pumped frequency-doubled Nd:YAG laser as the pump source. A maximum output power of 2.5 W is obtained for 16-W power of 532-nm pump light. A much higher conversion efficiency of 15.7% is obtained when at the maximum output power.     

Long-term frequency stabilization of a 16 m(2) ring laser gyroscope

A 16 m(2) helium-neon-based ring laser gyroscope has been frequency stabilized to within 60 kHz over a period of three months. This is achieved using the beat frequency of the ring laser and an iodine-stabilized reference laser as a feedback signal on a pressure vessel enclosing the entire laser, under servo control. We demonstrate that we can compensate for, and thereby negate the influence of, atmospheric pressure variations, which are considerable sources of long-term instability.     

A device based on a grazing-incidence grating for tuning the frequency of a single-mode dye laser

Numerical simulation methods have been used to study and optimize the mechanism based on grazing incidence of the radiation on a diffraction grating for scanning the frequency of a single-mode dye laser. The tuning mechanism uses a glass wedge (an optical reducer) placed in the laser cavity. It is shown that when this cavity is used it is possible by a special choice of parameters to avoid longitudinal mode hopping as the laser frequency is scanned over a broad range. Zh. Tekh. Fiz. 67, 53–57 (March 1997)     

激光陀螺稳频稳锁区控制参数测试系统

稳频稳锁区控制系统对提高激光陀螺的性能有着重要意义。设计了激光陀螺稳频稳锁区控制系统,并开发了稳频稳锁区控制参数测试系统。结合某型激光陀螺进行了试验验证。结果表明,该系统完全满足陀螺控制系统参数测试的需求,符合陀螺设计指标。     

Thermal characteristics of Nd~(3 )-doped fiber ring laser pumped by Ti:sapphire tunable laser

A Nd(3 )-doped fiber ring laser pumped by a CW Ti:sapphire tunable laser is reported. The characteristics of the system are studied for the first time at 77K and 300K. The results show a lower threshold and a higher slope efficiency at 77K than that at 300K. Applications of the Nd~(3 )-doped fiber ring laser in a multiplexing fiber sensor system and a fiber-ring-laser type temperature sensor are discussed.     

Optical frequency doubling of a single-mode dye laser in an external ring resonator

Optical frequency doubling of a single-mode cw Rhodamin 6G ring dye laser is performed with a thin angle-tuned LiIO₃ Brewster cut crystal in a stabilized passive ring resonator. A conversion efficiency of =5 mW uv/320 mW fundamental input power was achieved at =603 nm.     

Conditions for single-line and single-mode tuning of a CO2 waveguide laser

Single-mode tuning over 500 MHz in 90 lines, and 700 MHz in 70 lines is reported for a pyrex waveguide CO₂ laser in long-pulse operation. The peak power exceeds 100 W in the strongest lines, and the beam profile is diffraction limited. These features make the laser well suited as pump source for optically pumped molecular lasers.Work supported by the Danish National Science Research Council under Grant No. 11-3389     

Realization of a continuous frequency-tuning Ti:sapphire laser with an intracavity locked etalon

A continuous-wave all-solid-state tunable Ti:sapphire laser with compact configuration is presented. The frequency-tuning range extends from 760 to 825 nm by rotating the birefringent filters. When the intracavity etalon is locked on the oscillating frequency of the laser and the length of the resonator is scanned by the piezoelectric ceramics transducer, a maximal continuous frequency-tuning range of 15.3 GHz is realized. The obtained Ti:sapphire laser is successfully applied to scan the saturation absorption spectroscopy of D1 transitions of87Rb atoms around the wavelength of 794.97 nm.     

Short- and long-term frequency stabilization of a He-Ne laser using a Fabry-Perot cavity locked to the lamb dip

We have developed a frequency-stabilization system for the He-Ne laser using an external Fabry-Perot cavity which is locked to the Lamb dip of the laser. The cavity serves as a frequency discriminator for high-frequency noise suppression, while the length of the Fabry-Perot cavity is controlled, reffered to the Lamb dip, in order to eliminate low-frequency fluctuations. The frequency noise of a laser stabilized with the cavity suspended in a vacuum tank can be suppressed to about 1 $$0.1Hz/\sqrt {Hz} $$ at around 100 Hz by an FM-sideband locking method. The oscillation frequency is fixed to the Lamb dip at low frequency by controlling the cavity length thermally. The frequency fluctuation around the Lamb dip was estimated to be ～ 2.3 MHz.     

Intracavity spectrometer with a ring travelling-wave dye laser: Reduction of detection limit

In a ring travelling-wave dye laser a parasitic structure in the intracavity absorption spectrum is fully eliminated and a detection limit as low as 10^-10 cm^-1 is obtained. The sensitivity dependence of the intracavity laser spectrometer with travelling-wave cavity on the pumping level is also investigated.     

Intracavity configuration for tuning and obtaining simultaneous dual-wavelength operation from CW Nd:YAG laser

In this letter, a thin slab of glass is used as Fabry–Perot etalon inside a cavity of a continuous wave (CW) Nd:YAG laser to change the behavior of its output longitudinal modes. The slab etalon is used as tuning element when it turns around the laser cavity axis. Two simultaneous longitudinal modes with a relatively wide tuning range from 5.83 MHz to 0.02 THz are obtained when the Nd:YAG laser is operated at moderate output power of about 120 mW. The mode structure of this configuration is modeled and simulated. Computer-generated diagrams are also presented schematically and compared with the experimental results.     

900-nm Nd:Ti:LiNbO(3) waveguide laser

We report what is to our knowledge the first laser operation of Nd(3+) -doped LiNbO(3) near 900 nm. An absorbed power threshold of 26 mW was obtained when the device was pumped at 814 nm. The design of the waveguide geometry to favor laser operation at this wavelength is demonstrated.     

Low-threshold mid-infrared optical parametric oscillation in periodically poled LiNbO3 synchronously pumped by a Ti:sapphire laser

We report the generation of tunable high-repetition-rate optical pulses in the mid-infrared using synchronously pumped parametric oscillation in periodically poled LiNbO₃ (PPLN). Using a Kerr-lens-mode-locked Ti:sapphire laser as the pump source and a PPLN crystal incorporating grating periods of 21.0–22.4 μm, we have achieved wavelength conversion in the -–4 6μm spectral range in the mid-infrared. The use of a semi-monolithic cavity design and hemispherical focusing has permitted pulse generation in the strong idler absorption region of PPLN, resulting in a simple, compact, all-solid-state configuration with a pump power threshold as low as 17 mW and mid-infrared idler powers of up to 64 mW at 9% extraction efficiency. Signal output powers of up to 280 mW at 35% extraction efficiency are available over the -–1.004 1.140μm spectral range at 80.5 MHz and pulse repetition rates at harmonics of the fundamental frequency up to 322 MHz have also been obtained. Received: 5 December 2000 / Revised version: 23 January 2001 / Published online: 27 April 2001     

Calculating the spectral and time characteristics of a titanium sapphire laser

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 54, No. 1, pp. 69–73, January, 1991.