Browsing by Author "Wu, FH"

Now showing 1 - 7 of 7

Development of rewritable dual-layer phase-change optical disks
(2000)
Wu, FH
;
Hsieh, TE
;
Shieh, HPD
;
光電工程學系
;
Department of Photonics
Dual-layer optical disks comprised of two data layers were developed to study readout/write/erase characteristics. This disk was composed of recording layer land 2, of high transmittance and high reflectivity, respectively. Layer 1 and 2 of 15 and 20 nm increase transmittance and reduce writing power for recording. Only 1.5 mW laser power was sufficient for readout, 9 and 16 mW was required for recording on recording layer 1 and 2, respectively. Thse dual-layer disk can double data capacity on a disk substrate.
Optical switching layer for rewirtable volumetric optical disks
(2002-03-01)
Wu, FH
;
Shieh, HPD
;
光電工程學系
;
Department of Photonics
Owing to the presence of out-of-focus recording layers in volumetric optical disks. laser energy is decreased in reading/writing the targeted active layer. A non-linear optical material as an optical switch added to recording layers is proposed to modulate the optical characteristics of recording layers by diffraction limit laser spot impinged on it or not. The added optical switching structure can reduce laser energy and to increase recording sensitivity for reading and recording, respectively. Consequently. reading/recording on active layers of volumetric optical disks can be optimized.
Optical switching properties of VO2 films driven by using WDM-aligned lasers
(2006-04-10)
Tsai, KY
;
Wu, FH
;
Shieh, HPD
;
Chin, TS
;
光電工程學系
Vanadium dioxide (VO2) film had been demonstrated a high speed IR shutter driven by total optical modulation. However, it usually required a higher power heating laser of high power and precise optical systems to cover the probe beam on the sample with a heating beam of larger area. A new optical system, simply composed of wavelength division multiplexing (WDM), fiber lens or convex lens system, and a glass sheet with VO2 thin film on it, was easily assembled to utilize VO2 film as an IR shutter, implying the possibility to highly miniaturize the VO2-based optical shutter. A permanent low-transmittance (PLT) region forms on the film within the probe beam, resulting in a decrease in average power of the probe beam. Another ring-type switching area (switching ring) forms around the PLT region, resulting in the transmittance switching of the probe beam synchronously with the heating signal. VO2 films can be switched with the highest rate of a continuous square heating signal of 3 mW at 120 kHz. A heating pulse of 0.7ns and 13mW can be used to stimulate an IR pulse with fiber lens. (c) 2005 Elsevier B.V. All rights reserved.
Performance of a write-once multilayer optical disk that uses transparent recording material with an optical switching layer
(2004-10-10)
Wu, FH
;
Shieh, HPD
;
Huang, DR
;
Milster, TD
;
光電工程學系
A volumetric optical disk that has multiple transparent films with optical switching layers is used as a recording medium to increase the number of recording layers. In the disk the optical switching layer is adapted to reduce decay of laser energy and increase reading and recording sensitivity. Well-defined marks of similar to100-nm depth can be placed precisely on the transparent films by a focused laser beam. Writing and reading of a four-layer recordable disk, fabricated by molding and spin bonding, have been demonstrated experimentally. The volumetric disk can achieve a high recording capacity with conventional optical pickups. (C) 2004 Optical Society of America.
Thermochromism of silver oxide for optical switching layers in volumetric optical disks
(2002)
Wu, FH
;
Wang, CH
;
Hsieh, TE
;
Shieh, HPD
;
光電工程學系
Thermochromism of silver oxide for optical switching layers in volumetric optical disks
(2003-02-01)
Wu, FH
;
Shieh, HPD
;
光電工程學系
;
Department of Photonics
For reading and writing on a lower targeted recording layer of volumetric optical disks, transmitted laser power is decreased by absorption and reflection of the upper layers. Thus, a layer of thermo-chromatic material, such as silver oxide, has been added as an optical switching layer next to the recording layers to modulate the optical characteristics of the recording layers by the diffraction limited laser beam during writing. The optical switching structure can reduce peak writing laser energy by 42%. Consequently, optical switching layer is promising for volumetric recording to optimize R/W performance.
Write-once volumetric optical disk using transparent recording material with an optical switching layer
(2004-07-01)
Wu, FH
;
Shieh, HPD
;
Milster, TD
;
Huang, DR
;
光電工程學系
A volumetric optical disk having multiple transparent films with optical switching layers is proposed as a recordable medium to increase the number of recording layers. In the disk, an optical switching layer is adopted to reduce laser energy decay and increase recording sensitivity for reading and recording, respectively. A well-defined deformation area (mark) with submicron to nanometric dimensions can be yielded precisely on the transparent films by a focused laser beam. The peak writing power of 7 mW for a four-layer recordable medium, fabricated by molding and spin bonding techniques, was demonstrated experimentally as an example. The proposed volumetric disk can achieve a higher recording capacity by using conventional optical pickup units.