Recycling mirror

It is well known that by inserting an optical amplifier obtained by population inversion in an optical cavity, one can realize sources of coherent radiations, namely lasers. One can operate in the same way with parametric amphfication as shown on Fig. 1. A nonlinear crystal illuminated by an input pump is inserted in an optical cavity. This cavity is represented for convenience as a ring cavity but consists usually of a linear cavity. An important difference with the laser is that there are three different fields, insfead of one, which are presenf in the amplifying medium, all these fields being able to be recycled by the cavity mirrors. One obtain thus different types of "Optical Parametric Oscillators" or OPOs. 

Some deposits have been formed on Au single crystals. However, single crystals are too expensive to use in forming larger deposits, and have to be recycled. A number of disposable substrates have been investigated, so that the substrates do not have to be recycled, and the deposits can be kept around. The first deposits were made on cold-rolled gold foil, which proved too expensive, and polycrystalline after etching. Au vapor deposited on Si(lOO) at room temperature was used extensively, as the films were more reproducible and resembled Au mirrors. On the nanometer scale, however, the films consisted of 40 nm hemispheres (Fig. 5a). 

ABS is widely used for the interior and exterior parts of automobiles, and parts such as the console box, glove box, radiator grill, door mirror and others are recycled. Non-painted ABS parts exhibit good properties and surface appearance. Acrylic painted parts exhibit good properties but are partially rough in appearance. Urethane painted... 

Xe Fl, xenon flash lamps R, reflector IL, electrical isolation LT, laser tube connected with the gas recycling and cleaning system consisting of the pump, P, the thermostat, TH, and the vacuum device, V and are mirrors and LB is the laser beam. 

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