To explore the nonlinear absorption (NLA) properties of the SnO2 composite system, SnO2 / Ag / SnO2 (SAS) composited films were prepared by magnetron sputtering at room temperature. The NLA properties were investigated using femtosecond Z-scan technology at a wavelength of 800 nm. The results show that as the sputtering power of the Ag layer increases, the NLA type of the composite films changes from reverse saturated absorption to saturated absorption. According to the research results, adding the Ag layer can regulate the NLA type of composite films. In addition, by increasing the sputtering power of the Ag layer and the incident laser energy intensity, the NLA behavior of the composite films is improved. Compared with the monolayer SnO2 film, the NLA coefficient (β) of the composite film has increased by 17 times. We provide a new perspective for the application of SAS composite films in optoelectronic devices.
KEYWORDS: Compound parabolic concentrators, Light emitting diodes, Digital micromirror devices, Energy efficiency, LED displays, Zemax, LED lighting, Optical design, Projection devices, Chemical elements
A new optical engine consisting of LEDs, rectangular CPC, rectangular lens array and micro display chip DMD is
designed by using of KOLA illumination algorithm for micro-projection display. Detail description and analysis of the
rectangular CPC and rectangular lens array are provided. The influence due to the size of rectangular CPC and
rectangular lens array is analysed for illuminance uniformity on the DMD chip and light energy efficiency of the optical
engine system by software ZEMAX. Based on the analysis of parameter of rectangular lens array, the size of rectangular
lens array more decrease the illumination uniformity. Experimental results show that the proposed illumination light
optical engine can obtain perfect rectangular focula with higher light uniformity more than 90 % and higher energy
efficiency of 40 % to meet the needs of micro-projection display, at the same time the designed illumination optical
engine compared with other uniformizing light algorithm have advantages such as: lesser capacity, high illumination
uniformity.
A new phase measurement method is designed and presented by using the technique of signal shifting phase and the
technique of signal multiplication for laser rangefinder. The intensity of laser light is modulated by cosine circuit signal,
at the same time the cosine circuit signal is thansformed sine signal by the shifting phase technique. Two signals
mentioned above are multiplied by received signal from the target respectively, then being transmitted into signal
processor after passing through low band filter respectively. The result of phase-shift between the received signal and
sent signal is calculated by means of signal processor and time-counter with double frequency of modulation signal. The
proposed system is composed of four units such as control and count unit, emitting and receiving unit of laser light,
signal processing unit and result display unit. The two most advantages of proposed system over others are its ability of
proper isolation which reduces crosstalk and its independency thermal drift. Theoretical calculations and experimental
results have shown the accuracy better than 2 mm.
KEYWORDS: LCDs, Ferroelectric materials, Ceramics, Digital photography, Computing systems, Printing, Image processing, Control systems, Digital imaging, Liquid crystal on silicon
There mainly is laser digital photofinishing technique and digital photofinishing technique based on LCD
consisting of TFT and LCOS in the digital photofinishing field at the present time. The former have a good many
merit such as wide color gamut, high processing rate, large output size and high brightness, but his cost is very high,
his maintain technique being comparatively complex, that result in difficult use for people. The utilization ratio of
the latter is low because of lower resolution and lower aperture ratio for LCD, but the digital photofinishing based
on LCD have lower cost and higher utilization ration, being suitable for people's current standard of living.
Considering above mentioned problem, a micro-motion exposure method based on PZT piezoelectric ceramics
used in digital image photofinishing is presented. The two-dimension micro-motion exposure system consisting of
PZT piezoelectric ceramics, LCD panel, polarizing film and spring strip is designed. By means of PZT
piezoelectric ceramics the LCD panel is removed about the one half of the pixel size of the LCD panel for four
times from the original place, at the same time imaging system is exposed four times at the printing paper. The
software is used to control the time synchronization, the exposure time and motion range of the LCD panel. The
system has advantages such as shorter response time than 0.1seconds, lesser motion error than 0.01 microns, high
stability and repeatability. Experimental results show that the proposed micro-motion exposure method improve the
picture brightness and enlarge output size, at the meantime reducing the cost of the system.
A standard white light compounding algorithm based on combination of CCD illumination acquisition with computer
control is presented for LEDs. The computer adjust and control the working current of LEDs by using three-color LEDs
illumination acquired by CCD camera, achieved chromaticity coordinates error between compounded white light and
standard white light D65 less than the threshold beforehand setted by this technique, then acquiring needed standard white
light. Compounded white light meet the chromaticity error demand that is able to be changed, at the same time the CCD
illumination acquisition system is eliminated. The proposed algorithm improved the light energy utilization efficiency of
LED, and eliminated the offset of central wavelength and chromaticity coordinates due to work current change of LEDs.
Experimental results show that the proposed algorithm achieved lesser chromaticity error uv=0.001 relative to standard
white light D65, enhanced chromaticity uniformity of illumination field.
A standard white light compounding algorithm based on combination of chroma coordinates acquisition system with
computer working current control system is presented for three-color LED. The chroma coordinates acquisition system
consist of grating spectrometer and integrating sphere. The computer adjust and control the working current of
three-color LED, then achieved chroma coordinates error between the compounded white light and standard white light
D65, until the chroma coordinates is less than the threshold beforehand set by this technique. The compounded white
light meet the chroma error demanded that is able to be changed, at the same time the chroma coordinates acquisition
system and the working current control system are eliminated. The proposed algorithm the offset of central wavelength
and the change of chroma coordinates due to working current variety for LEDs. Experimental results show that the
proposed algorithm achieved lesser chroma error uv=0.001 relative to standard white light D65, enhanced chroma
uniformity of illumination field.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.