Extinction ratio

About: Extinction ratio is a research topic. Over the lifetime, 8541 publications have been published within this topic receiving 111908 citations.

Hybrid dielectric-loaded plasmonic waveguide and wavelength selective components for efficiently controlling light at subwavelength scale

Abstract: We analyze and design a hybrid dielectric-loaded plasmonic waveguide (HDLW) featuring a long propagation length and strong field confinement, for efficient control and confinement of light in the subwavelength area of λ2/160. The HDLW is then used to build compact wavelength selective components of high optical performance, including ring resonators (RR) and add-drop filters (ADF). In particular, we demonstrate RRs having a small ring radius of 2 μm, a low transmission loss of 0.8 dB, a high extinction ratio of 21 dB, and a free spectral range of 66 nm. Moreover, an ADF with a ring radius of 2 μm features a 12 dB extinction ratio, a transmission loss of 0.9 dB, and a channel isolation level of 10 dB at the resonant wavelength. The compact footprint and superior performance of these plasmonic components make them promising building blocks for future nanoscale electronic-photonic integrated circuits for data communication and sensing applications.

Mach-Zehnder optical modulator

Abstract: An optical modulator is provided that not only can realize a suitable initial operating point without using dc voltage for control, but that has little optical loss and can obtain an excellent extinction ratio. The optical modulator comprises: a substrate having an electro-optical effect, first and second branch optical waveguides formed in a first major surface of the substrate; an optical branching structure for splitting input optical signal and supplying the split signals to the branch optical waveguides; and a 3-dB directional coupler that couples the outputs of the first and second branch optical waveguides. The ratio of nonuniformity, which is represented by the difference in propagation constants of the two optical waveguides in 3-dB directional coupler, to the coupling coefficient of the 3-dB directional coupler is 1 to at least 5, preferably 1 to at least 15, and still more preferably, 1 to at least 20.

Refractive index and strain sensor based on twin-core fiber with a novel T-shaped taper

Abstract: A compact in-fiber Mach–Zehnder interferometer (MZI) based on twin-core fiber (TCF) with a novel T-shaped taper is proposed and demonstrated. The taper was firstly fabricated by a short section of TCF, and then spliced with a section of cleaved single mode fiber (SMF). When the light transmit into the TCF, multiple modes will be excited and will propagate within the TCF. In experiment, the proposed device had a maximum interferometric extinction ratio about 17 dB. And the refractive index (RI), strain, and temperature response properties of the sensor have been investigated, which show a relatively high RI, strain sensitivity and low temperature cross sensitivity. Hence, the sensor can be a suitable candidate in the biochemical and physical sensing applications. And due to its easy and controllable fabrication, the novel drawing technology can be applied to more multicore optical fibers.

Nonlinear optical loop mirror with an optical bias controller for achieving full-swing operation of gate switching

Abstract: Cross-phase modulation between counterpropagating lights degrades the extinction ratio of nonlinear optical-loop-mirror (NOLM) switches. To suppress such effect, we propose an NOLM with an optical-bias controller that can give a proper amount of optical bias between lights propagating through an NOLM in opposite directions. Implementing such optical bias controller in a conventional NOLM composed of a polarization-maintaining fiber, we demonstrate, for the first time, wavelength conversion of a nonreturn-to-zero signal under the full-swing condition with the maximum extinction ratio.

Analysis of CMOS Compatible Cu-Based TM-Pass Optical Polarizer

Abstract: A transverse-magnetic-pass (TM-pass) optical polarizer based on Cu complementary metal-oxide-semiconductor technology platform is proposed and analyzed using the 2-D method-of-lines numerical model. In designing the optimum configuration for the polarizer, it was found that the metal-insulator-metal (MIM) polarizer structure is superior compared to the insulator-metal-insulator polarizer structure due to its higher polarization extinction ratio (PER) and low insertion loss. An optimized MIM TM-pass polarizer exhibits simulated long wavelength pass filter characteristics of >;~1.2 μ.m, with fundamental TM0 and TE0 mode transmissivity of >;70% and <;5%, respectively, and with PER ~11.5 dB in the wavelength range of 1.2-1.6 μ.m. The subwavelength and submicrometer features of this TM-polarizer are potentially suitable for compact and low power photonics integrated circuit implementation on silicon-based substrates.