The relative dielectric constants of the cylindrical prism, metal, and dielectric material are 2.28, − 25 + j1.44, and 1.76 respectively. With advanced design and apodizing, flat-top transfer function can also be designed, and this type of AWGs are also commercially available. FBGs are periodic density variations inside fibers. There are two major advantages from introducing reconfigurable OADM technology based on WSSs. However, every technology has both strengths and shortcomings. Thus, the effective path difference between transmitted rays is also 2µt cos r. In this case, the phase difference between the waves is 180 degrees. 4 • Everyday Reflection • Reflection & Transmission (Normal Incidence) • Reflected & Transmitted Power • Optical Materials, Perfect Conductors, Metals TRUE or FALSE . The form of reflection undergo by the light waves at each boundary depends on the refraction indexes of the two mediums. Example gain equalization architecture for an undersea cable, including gain flattening filters (GFFs) in the amplifiers, and gain tilt equalization (GTE) and shape control filters (SCF) distributed along the amplifier chain. The undersea amplifiers operate in gain saturation, so that the output power remains constant independent of the input power changes. The following figure shows a Mach Zehnder waveguide molecular sensor. Two different technologies for equalizing filters can be used, either that based on in-fiber Bragg grating (IFBG) filters [42] or that based on thin-film filters (TFF). Static OADM filters can be configured in a single stage or in up to three consecutive stages. The bottom surface of the waveguide is a cladding material. It takes place at the upper boundary of the film. The gain equalization approaches that have been discussed so far have been based on passive optical devices, and are designed to produce an optimally gain flattened undersea cable at the time of installation. (11.45) and accepting only such β values that both the real and imaginary parts of kz1 and kzM are positive quantities. But the terms expressed in Eq. Additional OADM bands increase the unavailable bandwidth correspondingly. Find such matrixes. It is easy to see that the complex amplitudes of the uppermost layer and the lowest layer are related by: where A1 is the initially known amplitude of the incident field and BM=0 since the lowest layer is assumed to be semi-infinite in the z-direction, and therefore, there cannot be any reflected wave. The GFFs for undersea use must meet stringent system requirements, such as filter shape stability over temperature variations and system aging, low polarization dependent loss (PDL) and polarization mode dispersion (PMD), and small variation in average peak-to-peak filter shape between multiple devices of the same nominal design. A laser beam is reflected on an air-liquid interface. As OTM filters, they can provide access to a high number of wavelengths ranging from 32 to 96. In a TFF, thin dielectric, wavelength-selective layers are applied to a substrate (Figure 5.6). A higher filter contrast cannot be compensated for forever by an increase in the pump power for reliability reasons (see pump technology in section 4.5.2). Calculate the Poynting vector S and explain the result. Draw a sensor device design schematic, labeling key components. Δx/Lf is the diffraction angles in the output star coupler, Δx is the separation between adjacent output waveguides, j indicates the particular output waveguide number, ΔL is the length difference between two adjacent waveguides in the waveguide array, ns and nc are the effective refractive indices in the star coupler and waveguides, m is the diffraction order of the grating which is an integer, and λ is the wavelength. WDM filters provide access to all wavelength channels, where required. The same transfer matrix formalism that was developed to describe light transmission through thin film stacks can be used to find slab waveguide modes supported by the structure. For older types of filters (such as thin film filters or fiber Bragg gratings) about 200 GHz of bandwidth was needed between OADM bands; reducing available bandwidth for data transmission. However, the gain shape of the output power spectrum will tilt positively (with higher gain at longer wavelength and lower gain at shorter wavelength) when the amplifier gain is lower than the design value, and will tilt negatively (with higher gain at shorter wavelength and lower gain at longer wavelength) when the amplifier gain is higher than the design value. Figure 13.46. Because AWG is based on multi-beam interference, spectral resolution is primarily determined by the number of waveguides in the array between the two star couplers. The following figure shows a fiber-based glucose sensor design. As the primary equalization means, a GFF is installed in each optical amplifier. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. URL:, URL:, URL:, URL:, URL:, URL:, URL:, URL:, URL:, Advances in Dense Wavelength Division Multiplexing/Demultiplexing Technologies, Guided Wave Optical Components and Devices, The wavelength selectivity of an AWG is based on multipath optical interference. In each layer, kx=n1k0sinθ is constant due to Snell’s law. Different wavelengths, spaced at the free spectral range (FSR) of the filter, are accessible at the same output ports. (6.5.7) as, The maximum number of wavelength channels that an AWG can support within a FSR can be determined by. Fig. The reflection, refraction and diffraction of light waves is one strand of evidence. What is the intensity of transmitted light? We shall perform microscopic observation of a material whose absorption and scattering properties are given above. Second, the wavelength flexibility given by the WSS ROADM reduces the probability of “stranded capacity” on the fiber pair. A laboratory bought a new LDV, and two coherent laser beams of a wavelength of 650 nm intersect each other at the measuring point. Arrayed waveguide WDM filter. A sensitivity analysis of the circuit’s operation must be done to answer that question. What does SPR stand for? Step 7. Based on this expression, the separation of constructive interference wavelength between adjacent output waveguides can be found as, I the design of AWG, ΔL is usually a constant which determines the central wavelength λ0 through Eq. When light is travelling from rarer medium to denser medium, the phase shift is 180 degrees. Let us probe why the energy of the incident wave is not transferred in z direction.