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Organic Multiphoton Absorbing Materials and Devices
Published in Sam-Shajing Sun, Larry R. Dalton, Introduction to Organic Electronic and Optoelectronic Materials and Devices, 2016
Kevin D. Belfield, Sheng Yao, Mykhailo V. Bondar
Interchangeable media and backward compatibility, however, dominate optical storage. The data storage densities of magnetic media have reached 130 GB/in.2 in 2005, and it is expected that this will reach 200 GB/in.2 by perpendicular recording methods (Panasonic) in near future. For optical storage media, in theory, blue laser DVD technology can achieve data density up to 50 GB/in.2. However, both magnetic and conventional optical data storage technologies, where individual bits are stored as distinct magnetic or optical changes on the surface of a recording medium, are approaching physical limits beyond which individual bits may be too small or too difficult to store and retrieve.
Electro holography and active optics
Published in L. Vicari, Optical Applications of Liquid Crystals, 2016
The specifications for this device are given in table 2.12. Wave aberration produced at the defocused plane is approximated for correction. The results of the correction are shown in figure 2.61, which illustrates the actual wave-front and its approximation (a, b) and the residual wave aberration after correction (c). Figure 2.62 is the photographic representation of the device. The device has been developed for the blue laser beam whose wavelength is 405 nm. As the light absorption coefficient of ITO films, commonly used as transparent electrodes, increases several times when wavelength falls to 405 nm, its transmittance is reduced, which is the problem to be solved.
Introduction to Optical, Infrared, and Terahertz Frequency Bands
Published in Song Sun, Wei Tan, Su-Huai Wei, Emergent Micro- and Nanomaterials for Optical, Infrared, and Terahertz Applications, 2023
Song Sun, Wei Tan, Su-Huai Wei
Data storage. The Blue-ray technology in the computer, film, and gaming industries exploits blue laser of 405 nm to read and write the disc, which is able to store several hours of high-definition video. Recently, ultra HD Blu-ray discs (4K Blu-ray) and players have become available, allowing a storage capacity of 100 GB. More advanced technologies including using UV laser or Holographic Versatile Disc (HVD) are under development, which might further enhance the storage capacity to a few TB in a single disc.
Spectral and spatial dynamics of a multimode GaN-based blue laser diode
Published in Journal of Modern Optics, 2020
Watheq Al-Basheer, Taofeek O. Adigun, Abdulaziz Aljalal, Khaled Gasmi
Gallium nitride (GaN)-based blue laser diodes (LDs) are an interesting class of laser diodes that have attracted much attention due to their efficiency, compactness and economy [1–4]. These lasers have a wide range of applications in consumer electronics [2], remote sensing, underwater communications [1], trace gas detection [3,4], and in many other fields in modern science and technology [2]. Another important application of these laser diodes is in high-resolution spectroscopy where detailed knowledge of their emitted spectral characteristics is required [5–11]. Up-to-date, and despite their wide applications and many important enhancements concerning output power efficiency, device lifetime and beam quality, many fundamental properties of this class of lasers are not comprehensively understood. For example, a commonly observed discrepancy between the experimentally evaluated and the theoretically calculated longitudinal modes spacing has been frequently reported in literature as an anomaly [5–8]. Since most of the commercially available blue laser diodes are of a Fabry–Perot type with no external or internal feedback mechanisms, their emission spectra exhibit many longitudinal modes [7–10]. The intensity distribution of these modes is not smooth but rather has irregular shape [7,8]. Furthermore, knowledge of the laser diode’s longitudinal modes evolution, dynamics and temporal stability is crucial to understand their operation and usage in any useful application [4–10]. Henceforth, tracking the wavelength variation of each longitudinal mode with temperature and current is important in many applications, such as obtaining tunable single-mode laser with external cavity [12–16].