A laser device having an improved resonator utilizes a single rigid base component for a light reflector coating that defines and forms the end terminals of the resonator cavity, means being provided for translating and reflecting the laser beam between linear light paths that respectively terminate at the mirror surfaces provided by the coating. Various embodiments are shown and in which one or more prisms are used to fold the laser beam between offset and parallel light paths. The end terminal forming mirror surfaces may be coplanar and face in a common direction in the base component, or the mirror surfaces may be provided on opposite side surfaces of the component. Where the base component is made from transparent material the terminals may also be defined by the inside and outside surfaces of the coating. The use of figured surfaces in the unitary structure is contemplated and the use of mirror clusters for folding the beam is also contemplated. The rigid base component may be provided by a prism, a solid state laser rod, the envelope for a fluid lasing medium or any suitable rigid unitary structure that has an appropriate surfaces arrangement for the contemplated use.
A method and apparatus for producing preferential polarization of the output light beam from a laser of the kind having a three surface retroreflector comprises mounting the three reflecting surfaces of the retroreflector so that the surfaces are orthogonal in the retroreflector. The preferential polarization is obtained by controlling the combined effects of the orientation of the retroreflector assembly, with respect to the axis of the beam, and the selection of the coatings on the three reflecting surfaces.
A compact, powerful, single slab laser oscillator-amplifier system immersed in a high pressure gas which acts as a Raman shifting medium to shift the oscillator output wavelengths from the 1060-3000 nm range to the 1100-14000 nm range. The Raman shifting gas is conained within the casing (29) which also encloses a laser oscillator defined along the long axis of the slab laser medium (1) between dielectric mirror (2) and partially reflecting mirror (3). An electro-optic switch (7) is provided and slab (1) is pumped via a pump light source (22) while being cooled by Peltier stack (26). The slab also includes dielectric mirror (12) and anti-reflection coating (13) which act in conjunction with the slab laser medium (1) and the mirrored substrate (10) to form the amplifier portion of the system. Light passed from the oscillator through prism (4) is reflected by bevelled portion (9) of mirror (10) and directed to slab (1) where it is amplified and reflected by mirror (12). During successive reflections between slab (1) and mirror (10) a Raman shifted beam is generated and is emitted via collimator (19).
A fast axial flow laser includes a vessel which houses heat exchangers and a pump which imparts the pumping action throughout the laser. Only one housing is necessary and this housing can also be used as an optical bench for the resonator. In one embodiment a positive displacement rotary pump is utilized and a retoreflector included to mount three fold mirrors. In the folded configuration the retroreflector provides angular stability in any two orthogonal planes parallel to the laser beam.
A stable resonator for a ring-down cavity spectroscopy cell having an optic axis. The resonator includes two Brewster's angle retroreflector prisms, each having a plurality of total internal reflection surfaces. The prisms are disposed in alignment along the optic axis of the resonator. One or both of the prisms can be rotated so that light rays enter and leave a surface of the prism nearly at Brewster's angle to the normal of the prism surface. This feature maintains alignment between the prisms and allows the resonator to be tuned. One of the total internal reflection surfaces of at least one of the prisms may be a curved surface (either a ground curved surface or a surface curved by the addition, through optically contacting or gluing, of a plano-convex lens to the surface). Alternatively, an astigmatic lens may be centered in one arm of the resonator and tilted at Brewster's angle with respect to the optic axis of the resonator. In a preferred embodiment, each of the prisms has an apex angle of about 135.degree. minus Brewster's angle, a second angle of about 90.degree., and a third angle of about 180.degree. minus two times Brewster's angle.
A laser cavity assembly includes means (12, 13, 14; 14", 56, 57) defining respective optical resonance cavities (20, 22) for stimulated radiation of different wavelengths, which cavities include at least some common volume. Such means includes window means (13, 14) for emission of radiation amplified in the respective cavities. Means (15, 54) in one of said cavities is responsive to stimulated radiation emitted by a laser medium at one of the wavelengths to emit radiation at another of the wavelengths. Dual mode means (12, 54) has respective selectable first and second modes at which the laser cavity assembly is adapted to emit laser radiation predominantly at the respective wavelengths. Also disclosed are a novel Q-switch device and a combination laser oscillator and dual mode means.
