ABSTRACT
A laboratory experiment is discussed which simulates lidar fluorosensing of oil films on the sea surface at UV wavelengths. Three different mixtures of lasing gases, KrF, XeCl and N2 , were used while a fourth wavelength was given by a dye laser. It turns out that films having a thickness as low as 0.01 microm can be detected; the limiting factor resides mainly in the background fluorescence of water. Best results have been obtained with the XeCl excimer laser.
ABSTRACT
The simultaneous multiple line operation of a double pass dye laser amplifier is reported. Standard schemes have been used to generate two independently tunable lines and to scan one narrow line linearly around a fixed one. A simple, new scheme is illustrated, which allows symmetric splitting of narrow laser lines.
ABSTRACT
A new, simple scheme to tune a double-pass, superradiant dye laser is reported. A planar cell with a thickness below 100 microm filled with a highly concentrated (4-5 x 10(-)-M/liter) solution of Rhodamine 6G in ethanol is used. An unsaturated gain value of 1.7 cm(-) has been measured with flashlamp pumping, and the amplifier has been found to operate at a well saturated regime. Smooth laser linewidths ranging from broadband, gain narrowed values of 10 nm to narrowband values of 8 GHz have been achieved by using appropriate frequency dispersive feedback elements and suitable cell thickness. A 5-GHz output has been observed with a 25-microm gap cell. The absence of a resonant cavity avoids modal structure and ensures improved frequency and intensity stability. The reported configuration should be scalable up as far as output energy is concerned. Simultaneous two-wavelength operation is possible. Pumping with a frequency-doubled Nd-laser should allow a further reduction of the usable cell thickness with narrower output bandwidths.
Subject(s)
Laser Therapy , Lasers/instrumentation , Ophthalmology/instrumentation , Coloring Agents , Humans , Retina/surgeryABSTRACT
The present status of laser application in clinical ophthalmology is breifly reviewed. The potentials of tunable dye lasers as retinal photocoagulators are discussed. Selective irradiation of ocular tissues over the full visible spectrum and the simplicity and reliability of recently developed waveguide lasers are the most attractive features of these lasers. Waveguide dye lasers have permitted to set up very compact and simple retinal photocoagulators, with improved output intensity stability and nearfield distribution uniformity. Preliminary results obtained with pulsed Rhodamine 6G laser show that good retinal photocoagulations are obtained at very low output energies.
Subject(s)
Fundus Oculi , Laser Therapy , Lasers , Animals , Coumarins , Fluoresceins , Hydroxyquinolines , Rabbits , RhodaminesABSTRACT
A simple analysis of light amplification in media with inhomogeneous profile of the complex refractive index is carried out. The results are used to account for the waveguide effects observed in superradiant dye lasers with flashlamp excitation and to discuss the basic operations of some new dye laser configurations recently developed.
ABSTRACT
The influence of inhomogeneous distributions of gain and refractive index produced by the pumping radiationon the performance of dye laser amplifiers is discussed. Experimental measurements in capillary cylindrical cells and planar cells are reported for single-pass, double-pass, and ring configurations. Gain factors up to 8.5 x 10(4) have been obtained at low signal input with rhodamine 6G in ethanol. A saturated gain of 5 x 10(3) at 100-mJ output with an over-all efficiency of 0.1% has been achieved without full optimizationof the amplifier parameters. The reported results indicate that a two-stage double-pass amplifier driven by a dye laser oscillator in the milliwatt region can be used as an efficient high energy light source.
