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Reflective Optical Components
Published in Daniel Malacara-Hernández, Brian J. Thompson, Fundamentals and Basic Optical Instruments, 2017
Daniel Malacara-Hernández, Armando Gómez-Vieyra
Dielectric multilayer films are deposited by vacuum evaporation with a procedure that permits deposition of different kinds of materials with a precisely controlled thickness (see Chapter 32). Mirrors made in this manner are expensive. However, the great advantage is that the reflectivity at the desired wavelength range, the polarization state and the range of angles of incidence can be obtained as required. Unlike metal mirrors, they can reflect or transmit all of the incident light without absorbing anything; also, they can reflect some colors and transmit others. The dielectric mirror behavior is based on constructive interference between lights reflected from the individual thin film.
Optics Components and Electronic Equipment
Published in Vadim Backman, Adam Wax, Hao F. Zhang, A Laboratory Manual in Biophotonics, 2018
Vadim Backman, Adam Wax, Hao F. Zhang
High-reflection (HR) coatings function the opposite way from antireflection coatings. Rather than destructive interference between the reflected beams, thin films are chosen to yield constructive interference. The most common type of HR mirror is known as a dielectric mirror, where multiple thin layers of alternating dielectric material are deposited on a substrate such as glass or plastic.
Lasers
Published in Abdul Al-Azzawi, Photonics, 2017
The advantage of using mirrors for alignment is that they provide uniform performance over multiple laser wavelengths. Metallic mirrors offer the broadest wavelength performance. Dielectric mirrors offer a narrower reflectivity range but can provide higher peak reflectivity.
Switchable Fabry–Perot filter for mid-infrared radiation
Published in Liquid Crystals, 2019
U. Chodorow, R. Mazur, P. Morawiak, J. Herman, P. Harmata, P. Martyniuk
The filter was prepared by using two sandwiched quartz windows. The thickness of the cavity between windows was 4.3 ± 0.1 μm. On the inner side of the windows, indium tin oxide (ITO), dielectric mirror and alignment polymer films were deposited. The dielectric mirror was composed of seven layers of TiO2 and SiO2 arranged alternately. In Figure 1, the transmittance through one window without and with the mirror layer and the empty transducer is presented. The reflectance of the mirror is 95% around λ = 3.3 μm. The peak around 2.83 μm for the empty cell is not an interference peak but appears because the boundary of the mirror and the absorption peak for quartz window overlap. The peak around 3.57 μm is an interference peak inside the FP cavity, and extra peak for 3.14 μm appears due to the fact that windows are not flat enough and parallel.
Liquid crystal light valves as optically addressed liquid crystal spatial light modulators: optical wave mixing and sensing applications
Published in Liquid Crystals Reviews, 2018
S. Residori, U. Bortolozzo, J. P. Huignard
The general structure of an OASLM comprises two components: the photoreceptor and the electro-optic material, often separated by a dielectric mirror [3]. The input beam activates the photoreceptor which produces a corresponding charge field on the electro-optic material. In the retroreflective scheme, the reading light is modulated in its double pass through the electro-optic element. Since the readout can provide optical gain, the OASLM has also been called a light valve. Historically, several types of optically addressed liquid crystal-based SLM have been developed at the Hughes Research Laboratories, based on selenium or cadmium sulfide [4] or silicon [5–7] as the photoconductor and the liquid crystal, either in the parallel or twisted configuration, as the optical modulator [8]. Liquid crystal SLM based on amorphous silicon as the photoconductor have also been developed [9,10].
P-waves reflection in a semiconducting photothermal diffusion medium with initial stress and magnetic field
Published in Mechanics Based Design of Structures and Machines, 2022
The photothermal effect as a source of noise for LIGO was introduced by Braginsky, Gorodetsky, and Vyatchanin (1999), who observed that shot noise fluctuations in the interferometers’ laser power could drive surface fluctuations in the test masses. The way this is believed to happen is that the test masses’ dielectric mirror coatings absorb a small amount of light power, converting it to heat, which diffuses through the mirror. The theory for photothermal noise in a test mass substrate was worked out by Cerdonio et al. (2001) assuming that the laser spot is much smaller than the mirror dimensions and that the absorption of light and conversion to heat takes place in a thin layer at the mirror surface.