Current Issue : April - June Volume : 2018 Issue Number : 2 Articles : 5 Articles
An optical transmission system using Fiber Bragg Grating (FBG) and Erbium Doped Fiber Amplifier (EDFA) with new proposed\nmodel has been analyzed to overcome chromatic dispersion and attenuation phenomena. To evaluate the transmission system\nperformance of the received signals, a simple model of one channel transmission has been developed in the first step. Also, optical\nfiber length and attenuation coefficient parameters have been investigated in detail to deal with the optimized corresponding\nparameter values. Results show that the performance of the optimized design parameters is very efficient in terms of output power\n(dBm), noise figure (dB), gain (dB), and...
The overall thermal performance of a Parabolic Trough Collector (PTC) depends on its\noptical performance, particularly the uniformity of the irradiance distribution and the resultant\noptical efficiency of the collector. Local Concentration Ratio (LCR), optical efficiency and average\nlight concentration are three fundamental parameters of the optical performance of a PTC.\nThese parameters are affected by various optical and physical factors. The effects of these individual\nfactors on the performance parameters were investigated in this study using a verified Monte Carlo\nray tracing optical simulation model. The investigation revealed that all three performance parameters\nare directly related to the optical properties of the collector components. The values decreased gradually\nwith the increase of focal length of the mirror. Uniformity of the LCR profile was observed to decrease\nwith increasing rim angle and geometric concentration. Defocus dislocation of the receiver was found to\nimprove the uniformity of the LCR distribution by decreasing its peak concentrations, Cmax. Off-focus\ndislocation of the receiver, and inward angular deviation of the mirror profile were observed to\nincrease the Cmax and decrease the uniformity of the LCR distribition. Out-focus dislocation of the\nreceiver and solar tracking error distort the bi-symmetry of a normal LCR profile....
Tunable microoptics deals with devices of which the optical properties can be changed during operation without mechanically\nmoving solid parts. Often a droplet is actuated instead, and thus tunable microoptics is closely related to microfluidics. One such\ndevice/module/cell type is an optical shutter, which is moved in or out of the path of the light. In our case the transmitting part\ncomprises a moving transparent and electrically conductive water droplet, embedded in a nonconductive blackened oil, that is, an\nopaque emulsion with attenuation of 30 dB at 570nm wavelength over the 250 ...
In this paper, we demonstrated a continuous-wave intracavity singly resonant optical parametric oscillator based on periodically\npoled MgO:LiNbO3 (MgO:PPLN) pumped by a diode-pumped Nd:YVO4 laser at 1064 nm. The singly resonant optical parametric\noscillator only outputs the idler light as its cavity high reflectivitywas coated at the signal light.When the temperature was controlled\nat 120âË?Ë?C and the grating period set at 30.5 ...
The study proposes narrow-band imaging (NBI) lens design of 415nm and 540nm of a capsule endoscope (CE). The researches\nshow that in terms of the rate of accuracy in detecting and screening neoplastic and nonneoplastic intestinal lesions, the NBI\nsystem outperformed that of traditional endoscopes and rivaled that of chromoendoscopes. In the proposed NBI CE optical\nsystem, the simulation result shows the field of view (FOV) was 109.8�°; the modulation transfer function (MTF) could achieve\n12.5% at 285 lp/mm and 34.1% at 144 lp/mm. The relative illumination reaches more than 60%, and the system total length was\nless than 4 mm. Finally, this design provides high-quality images for a 300-megapixel 1/4â�³ CMOS image sensor with a pixel size\nof 1.75 �¼m....
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