The transfer matrix method has been used for the calculation of transmission and reflection properties of periodic and/or disordered dispersive photonic band gap (PBG) materials. We have studied the transmission prope...
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ISBN:
(纸本)0819414107
The transfer matrix method has been used for the calculation of transmission and reflection properties of periodic and/or disordered dispersive photonic band gap (PBG) materials. We have studied the transmission properties of: (1) PBG materials constructed of low resistive Si wafers forming the newly proposed layer-by-layer structure and exhibiting PBG at around 100 GHz; (2) a two-dimensional square lattice consisting of metallic wires; (3) materials having structural gaps close to a polariton gap.
A new rear cone decentration model has been implemented in the cylindrical resonator optical quality (CROQ) code, which simulates the performance of the ALPHA annular resonator. The new model avoids the traditional wa...
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ISBN:
(纸本)0819414107
A new rear cone decentration model has been implemented in the cylindrical resonator optical quality (CROQ) code, which simulates the performance of the ALPHA annular resonator. The new model avoids the traditional way of using equivalent phase tilts to simulate the decentration effect of optical elements in an optical train. Instead, it uses the approach of local field shift. As a result, the new model requires fewer Fourier components to represent the azimuthal variation of fields and thus largely extends the range of rear cone decentration that can be modeled by the CROQ code. The required memory space and CPU time for each decentration case are also significantly reduced.
A novel scheme to generate a subnanosecond pulse in VUV spectral region is proposed, by applying the dual-wavelength pumping method in conjunction with the polarization switching technique to the stimulated rotational...
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ISBN:
(纸本)0819414107
A novel scheme to generate a subnanosecond pulse in VUV spectral region is proposed, by applying the dual-wavelength pumping method in conjunction with the polarization switching technique to the stimulated rotational Raman scattering process. The optimum conditions for the short pulse generation are presented through the numerical calculations. The proposed process is applicable to a seed pulse generation for subnanosecond pulse amplification by the pump laser in the VUV region.
A numerical method for the analysis of the fast axial flow glow discharge C02 laser has been developed. The method is based on the self-consistent solution to the one-dimensional steady-state glow discharge equations,...
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ISBN:
(纸本)0819414107
A numerical method for the analysis of the fast axial flow glow discharge C02 laser has been developed. The method is based on the self-consistent solution to the one-dimensional steady-state glow discharge equations, the gas dynamic equations and the vibrational relaxation equations. The discharge equations include the continuity ones for the electrons, the positive and negative ions and Poisson's equation for the electric field. The three-mode relaxation model for the vibrational kinetics and the plane-parallel optical resonator model have been used. This approach does not require previous assignment of the discharge power distribution and enables obtaining the discharge structure included the near-electrode regions in addition to the laser characteristics.
An unstable resonator with a semitransparent output coupler is feasible for lasers with moderate gain and a large cross section of active medium. The resonator fundamental mode can be obtained up to Fresnel numbers of...
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ISBN:
(纸本)0819414107
An unstable resonator with a semitransparent output coupler is feasible for lasers with moderate gain and a large cross section of active medium. The resonator fundamental mode can be obtained up to Fresnel numbers of 10 and more. Output beam quality does not differ much from the Gaussian beam, but at the same time intensity distribution is rather flat and mode-medium coupling is better. This approach does not require the mirrors with tapered reflectivity profile. In practice the design of this type of resonator often requires the developer to place a spherical mirror inside to fold the optical path and that inevitably causes astigmatism. We describe the results of the investigation of resonator sensitivity to intracavity astigmatisms. The requirements for the resonator setup to obtain nearly unperturbed fundamental mode operation and a convenient resonator design to meet these requirements are discussed.
作者：
LINFOrd, GJTRW CO INC
DIV SPACE & TECHNOLSPACE & ELECTR GRPREDONDO BEACHCA 90278
lasers which oscillate within inhomogeneously broadened gain media exhibit spectral hole burning and concomitant reduction in output power compared with equivalent homogeneously broadened laser gain media. By increasi...
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ISBN:
(纸本)0819414107
lasers which oscillate within inhomogeneously broadened gain media exhibit spectral hole burning and concomitant reduction in output power compared with equivalent homogeneously broadened laser gain media. By increasing the cavity length, it may be possible to demonstrate at least a partial transition from an inhomogeneous laser cavity mode spectrum to a homogeneous spectrum. In neutral xenon lasers the inhomogeneous spectral broadening mechanism arises from Doppler shifts of individual atoms in thermal motion within the electric discharge comprising the laser gain medium. Optical transitions corresponding to these noble gas atoms have natural linewidths. simulations of the output power characteristics of the xenon laser were carried out as a function of laser cavity parameters, including the cavity length, L. These calculations showed that when the intracavity mode spacing frequency, c/2L < (Delta) (nu) n, the inhomogeneously broadened xenon mode spectrum converted to a homogeneously broadened oscillation spectrum with an increase in output power. These simulations are compared with experimental results obtained for the long laser oscillation characteristics of the (5d[5/2]2 degree(s) yields 6p[3/2]1) transition corresponding to the strong, high-gain 3.508 (mu) line in xenon.
Electronically excited oxygen, O2(1(Delta) ), is the power source that drives chemical oxygen iodine lasers. A new type of singlet oxygen generator has been both analytically and experimentally characterized. This new...
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ISBN:
(纸本)0819414107
Electronically excited oxygen, O2(1(Delta) ), is the power source that drives chemical oxygen iodine lasers. A new type of singlet oxygen generator has been both analytically and experimentally characterized. This new generator uses uniformly sized droplets of basic hydrogen peroxide (BHP) as the liquid phase reaction surface. The gaseous chlorine and O2(1(Delta) ) flow between a multitude of droplets in the generator. The fraction of chlorine that is converted into O2(1(Delta) ) depends on the coupled gas and liquid flow fields, diffusive mass transport, and homogeneous gas, liquid, and interface chemical reactions. A 1D flow/chemistry code has been developed and used to investigate the effects of the choice of parameters associated with the two-phase chemistry and transport on the chlorine utilization, O2(1(Delta) ) yield, and the efficiency of converting chlorine into O2(1(Delta) ). Predicted sensitivities to flow conditions, and the chemistry of the reactive media are presented. In particular, modeling results that identify dominant physical processes, and appropriate mathematical models are discussed. Analysis and a review of available information on the chlorine reaction with BHP in O2(1(Delta) ) generators indicates that the performance of the UDOG should be dominated by the gas-liquid interfacial and internal liquid chemical reactions and diffusion processes. A major part of the modeling effort has been to investigate this assumption and question it. A surface reaction model provides much better agreement with measurements made in a uniform droplet O2(1(Delta) ) generator.
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