Films lasers

Deposition of Thin Films. Laser photochemical deposition has been extensively studied, especially with respect to fabrication of microelectronic stmctures (see Integrated circuits). This procedure could be used in integrated circuit fabrication for the direct generation of patterns. Laser-aided chemical vapor deposition, which can be used to deposit layers of semiconductors, metals, and insulators, could define the circuit features. The deposits can have dimensions in the micrometer regime and they can be produced in specific patterns. Laser chemical vapor deposition can use either of two approaches. 

Selenium and selenium compounds are also used in electroless nickel-plating baths, delayed-action blasting caps, lithium batteries, xeroradiography, cyanine- and noncyanine-type dyes, thin-film field effect transistors (FET), thin-film lasers, and fire-resistant functional fluids in aeronautics (see... 

Figure 16.20. Micro-SERS spectra of FA films cast from solutions at (a) pH 5, (b) pH 8, and (c) pH 11 on 9-nm gold island films. Laser excitation at 785 nm and spectra were collected from different spots as marked on the optical image. Reprinted from Alvarez-Puebla et al. (2004).

Organic thin-film lasers with such a plastic substrate and the Spiro compound Spiro-40F as active medium have been shown [59]. This demonstrates the feasibility of the fabrication of low-cost organic DFB lasers in the UV-wavelength region. 

Oxide film laser lithography (OFLL) replaces the UV patterned photoresist of TMEMM by laser ablated patterned oxide mask, which is grown anodically on the titanium surface. OFLL can be appUed precisely to nonplanar complex surface and it also allows multilevel patterning. Fig. 12.11 shows that titanium cylinder surface consists of hemispherical cavities which are electrochemically micro-structured using OFLL. However, the process is serial and slower compared to TMEMM. 

Titanium cyiinder surface consists of hemispherical cavities fabricated by oxide film laser lithography [24]. 

With laser beams, materials can be precisely removed in a noncontact and reproducible manner. The ability to drill or machine a variety of materials, including metals, polymers, and ceramics, as well as composites and thin films, laser beams can be an efficient and economical tool in a number of industrial applications (O Neill 2004). 

Garcia, P., M. J. Mines, K. S. Bower, J. Hill, J. Menon, E. Tremhlay, and B. Smith. 2009. Robotic laser tissue welding of sclera using chitosan films. Lasers in Surgery and Medicine 41 (l) 60-67. 

Stress in anisotropic and patterned films laser beam... 

Figure 24 Typical Raman spectrum of -type doped carbon. Film laser wavelength = 632.8 nm dashed lines = spectral contributions solid line = fitting curve superimposed to the spectrum [59]. (Reproduced from Diamond and Related Materials, 8, Rzepka, E., et al.. Contribution of sp clusters in films and fibers obtained from camphor, pp, 481-484. Copyright 1999, with permission from...

Shamrakov D., Reisfeld R. Superradiant laser operation of red Perylimide Dye doped silica-polymethylmethacrylate composite. Chem. Phys. Lett. 1993 213 47-54 Shamrakov D., Reisfeld R. Super radiant film laser operation of perylimide dyes doped silica-polymethylmethacrylate composite. J. Opt. Mater. 1994 4 103-106 Sorek Y., Reisfeld R., Finkelstein I., Ruschin R. Sol-gel glass wave guides prepared at low temperature. Appl. Phys. Lett. 1993 63 3256-3258... 

In Sect. 6.2 we briefly describe the mechanism of electroluminescence for OLEDs, in order to identify the main parameters which influence performance. In Sects. 6.3 and 6.4, we discuss the luminescence of liquid crystalline semiconductors and the out-coupling of light from thin Aims with particular reference to the parameters identified in Sect. 6.2. The extended length of the aromatic core of liquid crystalline semiconductors results in a very high birefringence, as outlined in Sect. 6.5, which also discusses possible applications of birefringence for thin film lasers and photonic band-gap structures. Progress in chiral liquid crystal lasers is reviewed in Sect. 6.6 followed by a brief discussion and conclusion in Sect. 6.7. 

Although not widely investigated, the anisotropic properties of light-emitters have the potential to reduce the laser threshold in thin film lasers. In such an organic... 

Fig. 6.8 Schematic stnicture of an oigtmic thin film laser with distributed feedback provided by conugations of period A etched in the underiying silica substrate [6]...

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