Static Optical Recording Research Articles

Comparative Static Blu-Ray Recording Properties for Three Metal(II) Complexes in Spin-Coated Films

Smooth thin films of three metal(II) complexes were prepared by spin-coating process from 2,2,3,3- tetrafluoro-1-propanol solution and characterized atomic force microscopy (AFM). In order to examine their possible use as blu-ray recording media, the spin-coated films of the metal(II) complexes on K9 glass substrate with a silver reflective layer were evaluated by static optical recording testing system with a 406.7 nm laser. The morphologies of the thin films are smooth and have a root mean square surface roughness (RMS) of 0.34-0.41 nm with in 5 μ × 5 μ area. The results of the static optical recording test demonstrate that high reflectivity contrast (> 54 %) can be obtained at an optimum laser writing power and pulse width with high-to-low polarity, and the recording marks are durable even after 15000 times readout. In addition, the recording marks on the cobalt (II) complex thin film are very clear and circular, and their size can reach 200 nm or less.

Insights into the physical basis of metal(II) hydrazone complexes with isoxazole and barbituric acid moieties for recordable blu-ray media

Tetrafluoropropanol soluble, metal(II) hydrazone complexes derived from alkyl substituted isoxazole and barbituric acid were synthesized and evaluated as suitable optical recording materials for the recordable blu-ray disc system. The behaviour and relationships of the absorption, reflectivity and optical constants (complex refractive indices N = n + ik) for different metal(II) complexes in spin-coated films were discussed. In addition, the important thermal decomposition data of these metal(II) complexes from simultaneous TG–DSC analyses were presented as well. As an example of the utility of dye-based blu-ray recording media, we used the nickel(II) hydrazone complex thin film as recording layer for static optical recording performance test. Results showed that high reflectivity contrast over 45% and durable information marks (after repeatedly reading 20,000 times) could be achieved under optimum laser writing power and pulse width conditions, indicative of producing a very promising optical recording medium for blu-ray disc-recordable system.

Optical characterization and blu-ray recording properties of metal(II) azo barbituric acid complex films

Smooth thin films of nickel(II), cobalt(II) and zinc(II) complexes with azo barbituric acid were prepared by the spin-coating method. Absorption spectra of the thin films on K9 glass substrates in 300–700 nm wavelength region were measured. Optical constants (complex refractive index N = n + i k) of the thin films prepared on single-crystal silicon substrates in 275–695 nm wavelength region were investigated on rotating analyzer–polarizer type of scanning ellipsometer, and dielectric constant ɛ ( ɛ = ɛ 1 + i ɛ 2) as well as absorption coefficient α of thin films were calculated at 405 nm. In addition, static optical recording properties of the cobalt(II) complex thin film with an Ag reflective layer was carried out using a 406.7 nm blue-violet laser and a high numerical aperture (NA) of 0.90. Clear recording marks with high reflectivity contrast (>60%) at proper laser power and pulse width were obtained, and the size of recording mark was as small as 250 nm. The results indicate that these metal(II) complexes are promising organic recording medium for the blu-ray optical storage system.

Optical properties of nickel(II)–azo complexes thin films for potential application as high-density recordable optical recording media

Smooth thin films of three kinds of nickel(II)–azo complexes were prepared by the spin-coating method. Absorption spectra of the thin films on K9 glass substrate in the 300–600 nm wavelength region were measured. Optical constants (complex refractive index N = n + i k ) and thickness of the thin films prepared on single-crystal silicon substrate in the 300–600 nm wavelength region were investigated on rotating analyzer–polarizer type of scanning ellipsometer, and dielectric constants ε ( ε = ε 1 + i ε 2 ) , absorption coefficients α as well as reflectance R of thin films were then calculated at 405 nm. In addition, in order to examine the possible use of nickel(II)–azo complex thin film as an optical recording medium, one of the nickel(II)–azo complex thin film prepared on K9 glass substrate with an Ag reflective layer was also studied by atomic force microscopy and static optical recording. The results show that the nickel(II)–azo complex thin film is smooth and has a root mean square surface roughness of 2.25 nm, and the recording marks on the nickel(II)–azo complex thin film are very clear and circular, and their size can reach 200 nm or less.

Optical Recording Properties of Metal-Azo Dye as RecordingMedium with Super-Resolution Near-Field Structure

A novel metallized azo dye has been synthesized. Theabsorption spectra of the thin film and thermal characteristic aremeasured. Static optical recording properties with and without the Bimask layer super-resolution near-field structure (Super-RENS) of themetal-azo dye are investigated. The results show that the metal-azo dyefilm has a broad absorbance band in the region of 450–650 nm and themaximum absorbance wavelength is located at 603 nm. It is also foundthat the new metallized azo dye occupies excellent thermal stability,initiatory decomposition temperature is at 270°C and the mass loss isabout 48% in a narrow temperature region (15°C). The complexrefractive index N (N = n+ik) is measured. High refractiveindex (n = 2.45) and low extinction coefficient (k = 0.2) atthe recording wavelength 650 nm are attained. Static optical recordingtests with and without Super-RENS are carried out using a 650 nmsemiconductor diode laser with recording power of 7 mW and laser pulseduration of 200 ns. The AFM images show that the diameter of recordingmark on the dye film with the Bi mask layer is reduced about 42%,compared to that of recorded mark on the dye film without Super-RENS.It is indicated that Bi can well performed as a mask layer of the dyerecording layer and the metallized azo dye can be a promising candidatefor recording media with the super-resolution near-field structure.

Synthesis of nickel(II) complexes of α-isoxazolylazo-β-diketones and their absorption of spin-coating films and thermal properties for HD-DVD-R

Three kinds of new nickel(II) complexes of α-isoxazolylazo-β-diketones with blue-violet light absorption were synthesized. Their structures were postulated based on elemental analysis, MS and FT-IR spectra. Smooth films on K9 glass substrates were prepared using the spin-coating method. The absorption properties and thermal stability of these complexes were discussed. The static optical recording test for high density digital versatile disc-recordable (HD-DVD-R) system was also studied.

Optical near-field simulation of Sb thin film thermal lens and its application in optical recording

Using the finite-difference-time-domain method, the near-field optical distribution and properties of Sb thin film thermal lens are calculated and simulated. The results show as follows. Within the near-field distance to the output plane of thermal lens, the spot size is approximately 100nm, and its intensity is greatly enhanced, which is higher than that of incident light. The spot shape gradually changes from ellipse to round at the distance of more than 12nm to the output plane. The above-simulated results are further demonstrated by the static optical recording experiment.

Optical parameters and absorption of copper (II)-azo complexes thin films as optical recording media

Smooth thin films of three kinds of azo dyes of 2-(5′- tert-butyl-3′-azoxylisoxazole)-1, 3-diketones and their copper (II)-azo complexes were prepared by the spin-coating method. Absorption spectra of the thin films on a glass substrate in the 300–600 nm wavelength region were measured. Optical constants (complex refractive index N= n+ ik) and thickness of the thin films prepared on single-crystal silicon substrate in the 300–600 nm wavelength region were investigated on rotating analyzer–polarizer type of scanning ellipsometer, and dielectric constants ε( ε= ε 1+ iε 2), absorption coefficients α as well as reflectance R of thin films were then calculated. In addition, one of the copper (II)-azo complex thin film prepared on glass substrate with an Ag reflective layer was also studied by atomic force microscopy (AFM) and static optical recording. AFM study shows that the copper (II)-azo complex thin film is very smooth and has a root mean square surface roughness of 1.89 nm. Static optical recording shows that the recording marks on the copper (II)-azo complex thin film are very clear and circular, and the size of the minimal recording marks can reach 200 nm.

Static Optical Recording Properties of Super-Resolution Near-Field Structure with Bismuth Mask Layer

Super-resolution near-field structure (super-RENS) with bismuth (Bi) mask layer (Bi-super-RENS) is reported for the first time in this paper. Bi thin films with various thicknesses were studied by atomic force microscopy and grazing incident X-ray diffraction. Static optical recording tests with and without super-RENS were carried out using 650 nm semiconductor laser at recording power of 14 mW and 7 mW with pulse duration of 100 ns. The recording marks were observed by scanning electron microscopy and high-resolution optical microscopy with a CCD camera. Results showed that the Bi mask layer can also concentrate energy into the center of a laser beam at low laser power similar to the traditional Sb mask layer. Moreover, a (ZnS)80(SiO2)20 protection layer performed better than the SiN protection layer in the Bi-super-RENS. The direct observation of laser-recording marks may help better understand the working mechanism of the super-RENS, super-resolution ablation, and other nonlinear switch phenomena.

Optical and Thermal Properties of Nickel-Azo Dyes for DigitalVersatile Disc-Recordable

We investigate the absorption spectra, optical constants andthermal decomposition as well as red-light (650 nm) static recordingproperties of three novel nickel-azo dye films based on4-methylthiazole, benzothiazole and 6-methylbenzothiazole.Particularly, we obtain the nickel-azo complex film based on4-methylthiazole, peaking at 562 nm and 613 nm, with higher refractiveindex (n = 2.46) and lower extinction coefficient (k = 0.18) at thewavelength 650 nm and a sharp threshold of thermal decomposition at330°C. The results of the static optical recording test of thisdye film indicate that high reflectivity contrast of 51% can beobserved at a laser writing power of 5.9 mW and pulse width of 350 ns.These results imply that the nickel-azo complex based on4-methylthiazole is a promising candidate for a recording medium ofdigital versatile disc-recordable.

Spectral, Thermal and Green-Light Static Recording Propertiesof Nickel Phthalocynine Thin Film

We study the absorption and transmission spectra, the thermal stabilityand the green-light (514.5 nm) static optical recording properties ofnickel phthalocyanine (NiPc) thin film. It is found that this filmoccupies suitable absorption and transmission properties, excellentthermal stability (decomposition point > 600°C) and outstandingthermal decomposition characteristics (weight loss in one stepdecomposition >60%) for green-light (514.5 nm) optical recording. Highreflectivity contrast (>50%) was obtained at low writing power(5 mW) and short writing pulse-width (100 ns) using an Ar+ laser(514.5 nm) irradiation. Compared with azo in polymer films, thesubphthalocyanine film and Sb-Te-Based phase change films, theNiPc film has better green-light static recording properties. Theseresults indicate that metal phthalocyanine is not only a qualifiedmaterial for near infrared optical recording but also a promisingrecording medium candidate for green-light DVD-R.

Synthesis and optical properties of axially bromo-substituted subphthalocyanines

Subphthalocyanines (SubPc) are composed of three iso-indole units containing boron inside, which defines a molecular axis and forms a cone-shaped structure. Despite being non-planar, they show a delocalized 14π-electron system similar to that present in phthalocyanines. The attractive characteristics of SubPc are their chemical stability and thermal stability. In this paper, we report here the synthesis of five SubPc compounds, in which the axial substituent is a bromide. The peripheral substituent in the compounds leads to an improved solubility in common organic solvents such as ethanol and chloroform etc. The spectral and optical properties of these compounds were studied. The spectra and optical constants (refractive index, extinction coefficient) of the sublimed films of these SubPcs were measured by a spectrophotometer and an ellipsometer respectively. We also measured the static optical recording performance of these films with a thin Al (or Ag) reflective layer on them. These results demonstrated that SubPc showed a strong and broad absorption region near 600 nm and it will be a promising candidate for short-wavelength optical recording (such as DVD-R), if high-quality films can be got.

Short-wavelength static optical recording properties of subphthalocyanine thin films

The static optical recording properties of novel bromoboron trinitro-subphthalocyanine (BTN-SubPc) thin films were studied using a self-developed short-wavelength optical disk tester with high NA objective lens. High reflectivity contrast (>30%) was obtained at low writing power (8 mW) and short writing pulsewidth (200 ns) using the Ar+ laser (514.5 nm) irradiation. These results demonstrate that subphthalocyanine is not only qualified for red-light recording but also a promising candidate for the recording medium of a green-light DVD-R. The leading edge, just like the falling edge, of the dye’s absorption band can also be used to realize optical disk storage if an appropriate reflector was used. It provides a new clew for double-wavelength writing/reading and choosing short-wavelength recording materials.

Metallized thiazolylazo dyes as optical recording materials

A series of metallized thiazolylazo dyes have been designed and synthesized. Smooth films on optical glass and single-crystal silicon were prepared using the spin-coated method. The UV-Vis absorption spectra of the dyes were measured in solution and in films. The optical constant (complex refractive index N= n+ ik) of the films on single-crystal silicon has been determined using a scanning ellipsometer. The variation of the complex refractive index, N, with wavelength, λ, was obtained. From the value of n, k and the thickness of the dye films, the variation of the reflectance vs dye film thickness was then calculated. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) of the nickel thiazolylazo dye showed a clear threshold of thermal decomposition with a sharp exothermic park. Static optical recording tests were carried out. The results show that the nickel thiazolylazo dye is more suitable for use in short-wavelength diode-laser optical recording.

A Novel Organic Complex Thin Film for Rewritable Optical Storage

Erasable optical storage on an organic complex thin film m-nitrobenzal malononitrile and diamine benzene (m-NBMN/DAB) has been demonstrated. High contrast pattern can be produced by 780 nm laser pulses and can be erased by heating. The static optical recording characteristics were studied by the homemade static characterizer, and the structural properties of the thin films were investigated by the high resolution scanning electron microscope (HRSEM) and transmission electron microscope (TEM).

Optical recording performance of thin films of phthalocyanine compounds

As organic dyes with excellent thermal and light stability, phthalocyanine compounds have been investigated as write-once read-many optical recording materials. By selecting different substituents and metallic ions, the absorption bands of thin film of phthalocyanine compounds were matched with the wavelengths of semiconductor lasers. It was found that the absorption regions of vacuum sublimated thin films of vanadyl phthalocyanine (VOPc), tetra-pentyloxy phthalocyanine vanadyl (TPPcVO) and tetra-nonyloxy phthalocyanine vanadyl (TNPcVO) were between 580 and 850 nm. In the near-IR region, the absorbance and reflectivity of thin films of VOPc were greater than 50% and 20% respectively. The static optical recording test of the VOPc thin film showed that the write power was less than 10 mW with the write pulse width of 200 ns using an He-Ne laser as light source. The dynamic optical recording test of VOPc as a write-once read-many recording material on a 5.25 in optical disk indicated that the carrier-to-noise ratio (CNR) was greater than 45 dB.

Optical and recording properties of copper phthalocyanine films

Vacuum-sublimed films of copper phthalocyanine (CuPc) were prepared. The absorption spectrum and optical constants of the film were studied. It was found that there is a comparatively large absorption region at wavelength of 550 – 750 nm. A static optical recording test on a CuPc film on a glass substrate indicated that low power HeNe laser irradiation could initiate a relatively large reflectivity change. It has been observed that the introduction of a metallic reflective layer on the recording layer will raise the writing threshold energy and the maximum reflectivity contrast.

Optical recording behavior of tetra-neopentoxy phthalocyanine zinc Langmuir–Blodgett film

Langmuir-Blodgett films of tetra-neopentoxy phthalocyanine zinc (TNPPcZn) were prepared. Static optical recording behavior was tested in the Langmuir-Blodgett films of TNPPcZn. The reflectivity contrast was more than 100% in a writing and erasing cycle experiment. This is the first time to our knowledge that writing and erasing experimental data have been obtained in TNPPcZn film.