The propagation of a light beam through a photo-sensitive photopolymer Polyvinyl Alcohol/Acrylamide (PVA/AA), and the creation of self-written waveguides (SWWs), has received much attention. Here we explore the manufacture and characterization of SWWs in PVA/AA for applications at near infrared communication wavelengths 850nm and 1300nm. The SWWs are fabricated using visible light at wavelength 532nm. The insertion and optical loss of the SWWs at different wavelengths will be interrogated. An optical loss and attenuation profile is to be built up for each of the three wavelengths as they propagate down the resulting SWWs.
Optical waveguide trajectories formed in an AA/PVA a photopolymer material photosensitive at 532 nm are examined. The transmission of light by this materials is discussed. The bending and arching of the waveguides which occur are investigated. The prediction of our model are shown to agree with the observed of trajectories. The largest index changes taking place at any time during the exposure, i.e. during SWW formation are found at the positions where the largest light intensity is present. Typically, such as maxima exist close to the input face at the location of the Primary Eye or at the location of the Secondary Eyes deeper with in the material. All photosensitive materials have a maximum saturation value of refractive index change that it is possible to induce, which is also discussed.
The linear canonical transform (LCT) is used in modeling a coherent light-field propagation through first-order optical systems. Recently, a generic optical system, known as the quadratic phase encoding system (QPES), for encrypting a two-dimensional image has been reported. In such systems, two random phase keys and the individual LCT parameters (α,β,γ) serve as secret keys of the cryptosystem. It is important that such encryption systems also satisfy some dynamic security properties. We, therefore, examine such systems using two cryptographic evaluation methods, the avalanche effect and bit independence criterion, which indicate the degree of security of the cryptographic algorithms using QPES. We compared our simulation results with the conventional Fourier and the Fresnel transform-based double random phase encryption (DRPE) systems. The results show that the LCT-based DRPE has an excellent avalanche and bit independence characteristics compared to the conventional Fourier and Fresnel-based encryption systems.