Dye Laser Frequency Research Articles

UV radiation source on the basis of a nonlinear crystal with tunable 90° phase-matching

The results of investigations on the production of UV radiation sources tuned at the expense of the change of 90° phase-matching are given. At the change of a UV wavelength the 90° phase-matching is tuned at the expense of the change of dye laser frequencies. This method of tuning has special prospects for the production of supermonochromatic UV radiation sources on the basis of cw single-frequency organic dye lasers.

Long-term frequency and intensity stabilization of a cw dye laser

A method to stabilize the output frequency and intensity of a cw dye laser for periods of several hours is described. The dye laser frequency is controlled by a servo system which locks it to a Lamb-dip stabilized He : Ne laser to an accuracy better than 1 MHz with the help of a scanning Fabry-Perot interferometer. The dye laser intensity is controlled to better than 1% by direct control of the pumping source.

Fast frequency stabilization of a cw dye laser

A system is described for stabilizing a cw dye laser frequency to a high-finesse optical cavity. The length of this optical cavity is locked to a CH4-stabilized He-Ne laser with a tunable frequency-offset technique. A very fast servo system using an intracavity KD*P crystal), a long dye laser cavity, and the stabilized optical cavity result in an absolute frequency stability of 1 kHz for an integration time of 10−4 sec and 300 Hz for 300 sec. Intensity is stabilized to one part in 104.

Dye laser with a distributed feedback induced by second harmonic of neodymium laser

An investigation was made of different methods of tuning the stimulated emission lines of a dye laser with a distributed feedback induced by the second harmonic of a neodymium laser. The maximum tuning range for rhodamine 6G was 58 nm when the spectral width of the emission line was 0.1 A and the efficiency was 16%. A theoretical analysis was made and an experimental study was carried out of the conditions for the simultaneous stimulated emission of two or more dye laser frequencies in the presence of the corresponding number of spectral components in the pump radiation.

Frequency stabilization of a CW dye laser

A large improvement in the frequency stability of a single-mode cw dye laser has been obtained1 by using a wide-band (0–100 kHz) servo system to lock the dye laser frequency to a transmission fringe of a high-finesse optical cavity. By applying corrections to the optical length of the dye laser cavity, the free-running laser stability of ±50 MHz (for one second averaging time) was reduced to drifts of about 1 – 2 MHz/minute (corresponding to controllable drifts of optical cavity temperature and possibly of optical coupling parameters). The frequency has been made to track these drifts in a single cavity with errors less than 50 kHz rms for short times (20 µsec) and less than 100 Hz for long times (10 sec ).

Laser optical double resonance and efficient infrared quantum counter upconversion in LaCl3 : Pr3+ and LaF3 : Pr3+

In this paper, we report the first laser-excited optical double-resonance experiments in rare-earth-doped crystals. Infrared upconversion in LaCl3 : Pr3+ and LaF3 : Pr3+ has been achieved by means of a tunable cw dye laser pump. The quantum efficiency of the upconversion process at 2.03 μ in LaCl3 : Pr3+ is 1.2×10−3, which is an improvement of 4×105 over the highest efficiency found previously with incoherent sources. It is shown that an efficiency of 1 can be easily obtained with higher fluxes and improved crystal quality. Direct excitation of the output fluorescence from the 3P0 level is observed in both LaCl3 : Pr3+ and LaF3 : Pr3+ when the dye laser frequency is resonant with the states of the lower-lying 1D2 manifold in the absence of the infrared input. Detailed assignments of the observed double-resonance transitions have been made from wavelength and polarization measurements.

Locking of organic dye laser frequency to atomic resonance lines

Locking of organic dye laser frequency to atomic resonance lines

Self-induced Transparency and Dispersion Delays in Potassium Vapour

SELF-INDUCED transparency1 first demonstrated in ruby2 was subsequently reported3 observed in gaseous SF6. We wish to report the observation of this nonlinear transparency effect in the propagation through potassium vapour of coherent pulses of an organic dye laser, tuned to resonance with the λ7699 A (ground state 4S1/2–4P1/2) transition. Because linear and nonlinear dispersion delays may be confused with delays arising from self-induced transparency4,5 we have also investigated dispersion effects at frequencies away from resonance. The dye laser frequency can be readily tuned6 to resonance with transitions between single pairs of energy levels coupled to the laser field by dipole matrix elements, so complexities arising from degenerate transitions5 are avoided. Dye lasers covering the spectral range 3000 A to 11,000 A are now available and nonlinear coherent pulse propagation effects can thus be studied in many absorbing atomic vapours with our experimental arrangement which does not depend on the chance coincidence of a gas or solid-state laser frequency with a suitable electric-dipole transition in the material2,3.