Haobo Guo

Multi-wavelength optical storage of diarylethene PMMA film

Current commercial optical storage technologies are all based on the heat effect of the recording laser, i.e., heat-mode optical storage. In the present work, photon-mode optical storage using photochromic diarylethene materials was investigated. Two diarylethene derivatives were dispersed into PMMA solution, and spin-coated on a glass substrate with Al reflective layer as the recording layer. Two laser beams of 532 and 650 nm were used in recording and readout simultaneously, and signals with high S/N ratio were detected. Multi-wavelength optical storage was realized with the diarylethene PMMA film.

Efficient synthesis and photochromic properties of 2,3-position hybrid diarylethene derivatives

Abstract An efficient synthetic method was proposed to synthesize some 2,3-position hybrid diarylethene derivatives. In these compounds, one of thiophene rings was attached to the ethylene moiety at 2-position, the other at 3-position. These asymmetric diarylethenes are sensitive at wavelengths in the region of 400 and 500 nm. They can undergo thermally irreversible and fatigue-resistant photochromic reactions in solution, some of them even in the solid state. Substituent effects on their photochromism were examined.

Diarylethene materials for photon-mode optical storage

Photon-mode recording of photochromic materials is regarded as a promising storage system, which has various advantages over the traditional heat-mode recording in terms of its data capacity and data-recording rate. Diarylethenes show good thermal stability and remarkable fatigue resistance, and these properties are indispensable for the applications to optical storage materials. In present work, several diarylethene compounds were synthesized, and a series of optical storage tests were carried out on the sample discs with diarylethenes as the recording materials. The recording based on these photochromic materials was photon-type,and the recorded regions appeared as faded dots. 780, 650 and 532 nm lasers were used for writing on the corresponding discs, and the recorded information were readout by the same lasers respectively. A two-wavelength optical storage was realized on a mixed diarylethene recording layer by two laser beams of 532 nm and 650 nm synchronously. A higher data capacity can thus be expected to reach by using a multi-wavelength optical storage like that. Although the diarylethenes satisfy the minimum demands of optical storage systems, these molecules have one unsolved drawback: the lack of a non-destructive capability. In this work, Electric-locked properties were investigated in a BT3FP-OH thin film; the electric trigger could prevent the photochromic reactions, which provided a practicable non-destructive readout method. Three kinds of diarylethene derivatives linked by solvatochromic dye units wer fabricated; the theoretical investigation showed that reading at the wavelength of about 650-750 nm would destroy the recorded information no longer. Thus a non-destructive method could be constructed on these diarylethene molecules.

Synthesis and multiwavelength optical recording properties of two new photochromic diarylethenes

1,2-bis(2-methyl-5-(2-(1,3-dioxolane))-thien-3-yl)perfluorocyclopentene (1a) and 1,2-bis(2-methyl-5- 4-N,N-dimethyl-phenyl)-thien-3-yl)perfluorocyclopentene (2a) were synthesized and rewritable photo-mode muti-wavelength optical recording by the use of them was performed successfully. In amorphous film photochromic media, two laser beams of 532 nm and 650 nm were used in recording and readout simultaneously, and signals with high S/N ratio were detected. The results show that the reflectivity difference between the recorded dot and unrecorded region is greater than 50%, and above all, there is no crosstalk existing in the two diarylethenes, which it is very important to implement successfully multi-wavelength optical recording. The photochromic properties of them were also discussed.

Two-photon induced fluorescence of diarylethene molecule

A diarylethene derivative with thermally irreversible photochromic reactivity and good fatigue resistance has been synthesized. The two-photon-induced fluorescence of the compound is observed by excited with 800 nm beam. The intensity of the fluorescence is found to be proportional to I1.748, where I is the incident laser intensity, and decays with the increase of irradiation time. The results show that two-photon induced nonlinear photochromic reaction was partially realized. It demonstrates that the compound is a promising candidate for two-photon 3D optical data storage.

Multiwavelength optical storage of diarylethene PMMA films

Current applied optical storage technologies are all based on the heat effect of the recording laser, i.e., heat-mode optical storage. In the present work, photon-mode optical storage using photochromic diarylethene materials was investigated. Two diarylethene molecules dispersed into PMMA together was used as storage material. The recording layer was spin-coated on a glass substrate with Al reflective layer. Two laser beams of 532 nm and 650 nm were used in recording and readout by simultaneously writing and reading, and the reading lasers detected signals with high S/N ratio. Multi-wavelength storage was realized with the diarylethene PMMA film.

Diarylethene-based photochromic rewritable optical storage media for short-wavelength recording

Two non-symmetric perfluorocyclopentene derivatives have been synthesized. The absorption bands of their closed forms are located at 400 to approximately 500 nm wavelength regions. They undergo thermally irreversible photochromic reaction and fatigue resistant. The closed-ring form remains thermally stable after several months. And the repeatable cycle number in hexane is more than 103 times in the presence of air. It demonstrates that they are promising candidates for short wavelength recording.

Synthesis and photochromic properties of diarylethene derivatives

Four photochromic diarylethenes with different spectra in open and closed form were synthesized simultaneously. Irradiation of the open form with UV light results in essentially quantitative photocyclization to the closed form. The compounds show attractive optical properties and are expected to be used in optical storage and photoswitch.

Investigation of nondestructive readout of diarylethene with electronic gated reactivity

Diarylethene has good applicative perspective in optical memories for its photochromic property. But, the most important problem, which prevents the diarylethene from practical application, is the Non-destructive readout capability. In this paper, we synthesized a diarylethene derivative -- compound 1 (See Figure 1) that has photochromic and electrochromic activity. It has good electronic gated reactivity in solution. And, we found the gel electrolytes based on PMMA are good materials of film for the compound 1. In this film, compound 1 shows almost the same phenomenon as that in solution. This gated reactivity capability provides a good support for the practical application of diarylethene.

Synthesis and photochromic properties of asymmetric diarylethenes

Two asymmetric photochromic diarylethenes with different spectra in open and closed form were synthesized simultaneously. Irradiation of the open form with UV light results in essentially quantitative photocyclization to the deeply colored form. The compounds show attractive optical properties and are expected to be used in optical storage and photoswitch.