Locking of a cw dye laser to inverted atomic transitions

We have observed narrow line oscillation of an internally pumped cw dye laser at wavelengths which correspond to atomic transitions in the pump laser discharge. At other discharge wavelengths quenched regions in an otherwise broader dye laser output have also been observed. It is believed that the narrow lines correspond to transitions which have gain in the pump laser discharge, while the holes correspond to transition with loss.     

Locking of a flashlamp-pumped dye laser at small injection powers

Experiments have been carried out on the injection-locking of a pulsed dye laser to an argon-laser-pumped CW dye laser of 50 MHz linewidth without longitudinal mode matching. With the inclusion of a Fabry-Perot etalon within the ring laser arrangement of the pulsed laser, the initiation of injection locking and saturation occur at low injection powers.     

Investigation of the population inversion in a He-Ne laser discharge by heterodyne holographic interferometry

Heterodyne holographic interferometry was used for end-on investigation of a He-Ne laser discharge. By tuning an actively stabilized dye laser over the 633 nm neon atomic line the phaseshift was obtained as function of frequency, thus enabling the determination of spatially resolved population inversion.     

Locking the laser frequency to an atomic transition

A simple method for stabilizing the laser frequency to an atomic transition is described. It makes use of the frequency shift caused by the Doppler effect. With this method the frequency of a dye laser can be kept tuned to an atomic resonance line within 10% of the linewidth for periods of several hours.     

Doppler-free frequency-modulation spectroscopy of atomic erbium in a hollow-cathode discharge cell

The erbium atomic system is a promising candidate for an atomic Bose–Einstein condensate of atoms with a non-vanishing orbital angular momentum (L≠0) of the electronic ground state. In this paper we report on the frequency stabilization of a blue external cavity diode laser system on the 400.91 nm laser cooling transition of atomic erbium. Doppler-free saturation spectroscopy is applied within a hollow-cathode discharge tube to the corresponding electronic transition of several of the erbium isotopes. Using the technique of frequency-modulation spectroscopy, a zero-crossing error signal is produced to lock the diode laser frequency on the atomic erbium resonance. The latter is taken as a reference laser to which a second main laser system, used for laser cooling of atomic erbium, is frequency stabilized.     

A CW CO chemical laser based on a hollow-cathode discharge

We report on a small-scale CW chemical CO laser using a hollow-cathode discharge for atomic oxygen production. This kind of discharge exhibits several unique properties which make it an ideal source of atomic oxygen. The construction and operation are simple and the design very compact. A specific laser energy of 100 J g^-1 and laser outputs of 9 W were obtained with an active length of 7.5 cm.     

A mirror-free cavity configuration for a CW ring dye laser

A new cavity configuration without mirrors is described for a CW ring dye laser. The cavity design is based on a new type of focusing prism which uses the Brewster angle of incidence and total internal reflection. Special roof prisms allow wavelength tuning. All of these elements are made from uncoated quartz thus allowing dye laser operation over a large range of wavelengths. CW operation as well as synchronously pumped mode locked operation with intracavity doubling is reported using the Rhodamine 6G dye.     

Laser-induced fluorescent measurements of magnetic field contoursin a low-pressure discharge

Faraday rotation of a laser beam and emission spectroscopy to resolve Zeeman splitting provide information about the plasma magnetic field, integrated along the line of sight. Information about the local magnetic field strength can be obtained using a dye laser tuned off the center of an atomic or ionic transition by an amount δλ_z. If the absorption linewidth of the transition probed is less than the Zeeman splitting, only those atoms/ions residing in a magnetic field where the Zeeman splitting is δλ_z will resonantly absorb energy from the laser and fluoresce. The feasibility of this magnetic field contour technique was studied in a low-pressure neon discharge. A conductor insulated from the discharge generated a large magnetic field in the discharge free of the Stark broadening effects associated with large plasma currents. The laser-induced fluorescence (LIF) intensity profile measured along the laser beams had peaks at those spatial locations where local magnetic fields, inferred from the conductor current, agreed with the Zeeman shifted wavelength of the laser     

Flashlamp pumped tunable dye laser of ultra-narrow bandwidth

A flash lamp pumped dye laser with a ring cavity is injected with the light beam coming from a stabilized singlemode c.w. dye laser. The light emitted by the pulsed laser is analysed either by a Fabry Perot etalon, or by producing a Doppler-free two-photon transition. The bandwidth of the pulsed laser is identical to the one of the c.w. laser; but the pulsed light is shifted to higher frequency by an amount of a few MHz.     

外腔谐振技术及其应用

本文叙述了连续单模染料激光在外腔谐振中增强的原理,外腔的构成,介绍了外谐振腔在无多普勒光谱测量中的应用,特别在单模连续染料激光倍频中,应用这种外谐振腔使倍频转换效率提高百余倍。     

High-resolution spectroscopy with and frequency stabilization of a cw dye laser

The hyperfine splittings of the Na D₁ and D₂ lines were investigated using a single mode cw dye laser. The light of the laser was scattered by the atoms of an atomic beam and the fluorescent light was observed as the frequency of the laser was tuned across the D lines. The Doppler width of the atomic beam was reduced to about 2.5 MHz so that the absorption width of the atoms of the beam was essentially determined by the natural width of the 3²P_1/2 and 3²P_3/2 levels, which is about 10 MHz. Since the linewidth observed for the hyperfine transitions was 30 MHz, most of the hyperfine components of the D₁ and D₂ lines could be resolved. In another experiment the frequency of the dye laser was locked to a hyperfine transition of the D₁ line. The observed variation of the output frequency of the dye laser was less than ±1.5 MHz. In addition, the intensity of the dye laser was controlled to about 10⁻³, using an electro-optically variable transmission filter.     

Directed motion of neon atoms in a DC discharge of a ring laser

Radiation trapping is taken into account in the calculation of frequency differences in a ring laser at the disbalance of discharge currents caused by the directed motion of atoms. The motion of neon atoms is caused by the pressure difference between the anode and cathode, by the dissociative recombination of molecular neon ions, and by the resonance recharging of ions. The results obtained allow the partial contributions of these mechanisms to the atomic motion to be determined and the atomic velocities and concentrations to be estimated.     

Frequency-locking of a CW dye laser to some absorption lines of a neon discharge by a Faraday filter

Single-mode oscillations of a CW dye laser at the center of five absorption lines from the 1s states to the 2p states of neon were obtained by means of a neon discharge Faraday filter, without any other frequency-selective elements. The most striking thing observed is that saturated absorption takes place at the center of several absorption lines in a Faraday filter, in addition to optical rotation.     

Generation of 10-GHz ultra-short pulses with low time jitter in an actively mode-locked fiber laser

We have experimentally achieved the 8.3-ps ultra-short pulse at 10 GHz repetition rate with the time jitter as low as 590 fs in an actively mode-locked fiber ring laser. The ring-cavity laser is mode-locked by a semiconductor optical amplifier based on cross-gain modulation. The external CW source is modulated with radio frequency signal by an amplitude modulator as the external optical pulses and, then, injected into the fiber ring cavity to achieve active mode locking. Further investigating the laser output characteristics, it indicates that the linewidth of employed CW source affects properties of the generated ultra-short pulse, such as phase noise and time jitter. Ultra-short pulse at high repetition rate with low time jitter can be generated by the optimization of CW laser source.     

CW laser oscillation in a hollow cathode He-Kr discharge

CW laser oscillation on the 4694 Å transition of Kr II has been observed in a hollow cathode He-Kr discharge.     

CW laser oscillation in a hollow cathode HeAr discharge

CW laser oscillation was observed at the 4765 Å transition of Ar II in a hollow cathode HeAr discharge.     

Pulsewidth and interpulse jitter measurements of a passively mode-locked ring CW dye laser

Pulsewidth and jitter measurements have been carried out on a passively mode-locked Rhodamine 6G CW ring dye laser using the SHG autocorrelation technique and a synchroscan streak camera respectively. The pulse durations were measured to be ≈0.18 ps and the cumulative long-term jitter was deduced to be subpicosecond.     

A frequency-doubled frequency-stabilized cw ring dye laser for spectroscopy: A study of the λ = 293.3 nm transition in In1

In this letter a frequency-doubled frequency-stabilized CW ring dye laser for the wavelength region 292–305 nm is described. 500 μW U.V. power combined with a 2 MHz linewidth and a 7 GHz scanwidth has been obtained by intracavity frequency doubling in an ADA crystal. The set-up has been tested on the hyperfinestructure of the λ = 293.3 nm transition 5p²P_{$\text{3}\text{2}$} → 7s²S_{$\text{1}\text{2}$} in In1.     

Frequency offset locking of a synchronously pumped mode-locked dye laser

We have developed a scheme of frequency offset locking for transferring the frequency stability of a commercial dye laser to a synchronously pumped mode-locked dye laser. By observing the beat frequency between the two dye lasers, mode stability of less than 2 MHz has been observed for the mode-locked dye laser mode. The use of the mode-locked system as a spectroscopic tool has been demonstrated by observing Doppler-free multiple pulse two photon spectra of the sodium 3S-4D transition.