A split-flow laser cooling assembly for providing separate cooling environments for the pumping medium and the laser medium. The device includes a generally transparent monoblock, a pumping medium for providing pump light, and a laser medium responsive to the pump light for generating laser energy. The monoblock is generally transparent and has a first open bore and a second open bore oriented with axis' parallel to each other. The first bore receives the pumping medium such that a pump cooling passage is provided between the monoblock and the pumping medium. Likewise, the second bore receives the laser medium such that a laser cooling passage is provided between the laser medium and the monoblock.
A vertical cavity surface emitting laser with a mode-selective mirror. A filter is formed on the top DBR stack of a VCSEL. The filter includes semiconductor layers that are etch stops for immediately superior layers. The filter is selectively etched to create a first region that is phase matched to the top DBR stack and a second region that is phase mismatched to the top DBR stack. The second region inhibits undesired modes and provides additional absorption for the undesired modes. The first region is formed using a wet-etch process whose etch depth is controlled because the semiconductor layers are etch stops for immediately superior layers.
An optical resonator has an axial mode frequency tuning rate with respect to temperature matching the peak gain frequency tuning rate, so that mode hops are eliminated. The resonator contains a composite cavity consisting of a gain medium and free space. Preferably, the resonator is a single-frequency solid state laser containing a solid state gain medium defining a physical path length L.sub.g. The optical cavity is defined by a high reflector and output coupler surrounding the gain medium and defining a physical cavity path length L.sub.o. The high reflector and output coupler are mounted on a substrate so that L.sub.o is temperature insensitive. Preferably, the substrate is a thermally insensitive material having a negligible coefficient of thermal expansion; for example, it may be Invar.TM., Super-Invar.TM., ULE.TM. Glass, Zerodur.TM., and fused silica. Alternately, the substrate is a thermally isolated material that is temperature controlled and insulated from the gain medium. When L.sub.o =L.sub.g, the axial mode tuning rate has a greater magnitude than the peak gain tuning rate. However, L.sub.o /L.sub.g is fixed and designed so that the axial mode tuning rate is identical to the peak gain tuning rate. In particular, ##EQU1## The laser preferably contains means for ensuring single-frequency operation. For a ring laser, it may include a magnet and half-wave plate inside the cavity, coupled with rod-shaped gain material with anti-parallel Brewster facets. For a non-planar ring oscillator, the purpose of the half-wave plate is instead served by the non-planar path. Alternately, the resonator is an optical parametric oscillator.
A hand-held laser device includes a casing formed with a substantially hollow interior space and having a laser emitter thereinside. The laser emitter is formed with an exciting lamp and a laser rod. A source generating a stream of gaseous coolant is provided within the interior space. A fluid cooling arrangement at least partially surrounding the laser rod is disposed within the stream of gaseous coolant for heat removal therefrom.
A hand-held laser device includes a casing formed with a substantially hollow interior space and having a laser emitter thereinside. The laser emitter is formed with an exciting lamp and a laser rod. A source generating a stream of gaseous coolant is provided within the interior space. A fluid cooling arrangement at least partially surrounding the laser rod is disposed within the stream of gaseous coolant for heat removal therefrom.
A cooling system having a single circulator cools a laser, laser power supply, and laser light valve using two parallel cooling loops having different flow rates. Independent protection against an over temperature condition of the laser, laser power supply, and/or laser light valve is provided in each cooling loop.
