# US 2017/0285441 A1 · Photonic crystal all-optical d-type flip-flop > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0285441 A1 - Document ID: US20170285441A1 - Status: Published application - Kind: A1 - Application number: 15/626,206 - Filed: 2017-06-19 - Published: 2017-10-05 - Earliest claimed: 2014-12-19 - Assignees: Zhengbiao Ouyang - Inventors: Zhengbiao Ouyang; Quanqiang Yu - Web page: https://patentgrep.com/patent/US20170285441A1 ## CPC - G02F 3/00: Optical logic elements; Optical bistable devices - G02B 6/1225: {comprising photonic band-gap structures or photonic lattices} - G02B 6/3544: {2D constellations, i.e. with switching elements and switched beams located in a plane} - G02F 1/3511: {Self-focusing or self-trapping of light; Light-induced birefringence; Induced optical Kerr-effect} - G02F 1/365: in an optical waveguide structure (G02F1/377, {G02F1/395} take precedence) - G02F 2201/06: integrated waveguide - G02F 2202/32: Photonic crystals - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract A photonic crystal all-optical D-type flip-flop includes an optical switch unit, a photonic crystal structure unit including two signal-input ends, a signal-output end and an idle port, a wave absorbing load and a reference-light source; the clock signal-input port of the photonic crystal structure unit is connected with a clock control signal; a second port of the photonic crystal structure unit is an intermediate signal-input port, said intermediate signal-input end of the photonic crystal structure unit is connected with a first intermediate signal-output end of the optical selector switch; a logic signal is connected with the first signal-input end of the optical switch unit; the absorbing load is connected with a second intermediate signal-output end of the optical switch unit; said reference-light source is connected with a second signal-input end of the optical switch unit, which is a reference-light input end connecting with the output end of said reference-light source. ## Claims ### Claim 1 A photonic crystal (PhC) all-optical D-type flip-flop, wherein said PhC all-optical D-type flip-flop, comprising: an optical switch unit, a PhC structure unit, a wave absorbing load and a reference-light source; said PhC structure unit includes two signal-input ends, a signal-output end and an idle port; a first port of said PhC structure unit is a clock signal-input port, and said clock signal-input port is connected with a clock control signal CP; a second port of the PhC structure unit is an intermediate signal-input port, said intermediate signal-input end is connected with a first intermediate signal-output end of said optical selector switch; a logic signal D is connected with the first signal-input end of said optical switch unit; said absorbing load is connected with a second intermediate signal-output end of the optical switch unit; said reference-light source is connected with a second signal-input end of the optical switch unit; said second signal-input end is a reference-light input end, said reference-light input end is connected with the output end of said reference-light source. ### Claim 2 (depends on 1) The PhC all-optical D-type flip-flop of claim 1, wherein said PhC structure unit is a two-dimension.al (2D) PhC nonlinear cavity, and a center of said 2D PhC cross-waveguide nonlinear cavity is formed by arranging twelve rectangular high-refractive-index linear-dielectric pillars and one square nonlinear-dielectric pillar in a quasi- one-dimensional (1D) PhC manner in a longitudinal waveguide direction and a transverse waveguide direction, the central square nonlinear-dielectric pillar attaches to four adjacent rectangular linear-dielectric pillars, said central square nonlinear--dielectric pillar is made of a Kerr type nonlinear material, and has a dielectric constant of 7.9 under low-light-power conditions, a second rectangular high--refractive--index linear-dielectric pillar has said dielectric constant consistent with that of said nonlinear-dielectric pillar under low-light-power condi)ns. ### Claim 3 (depends on 1) The PhC all-optical D-type flip-flop of claim 1, wherein said high-refractive-index linear-dielectric pillars of said nonlinear cavity unit includes a 2D PhC cross intersected waveguide four-port network, two mutually-orthogonal quasi-1D PhC structures are placed in two waveguide directions crossed at said center of across waveguide, said dielectric pillar is arranged in a middle of said cross waveguide., said dielectric pillar is made of a nonlinear material, and said quasi-1D PhC structures and said dielectric pillar constitute a waveguide defect cavity. ### Claim 4 (depends on 1) The PhC all-optical D-type flip-flop of claim 1, wherein said PhC is a 2k+1)x2k+1) array structure, where k is an integer more than or equal to 3. ### Claim 5 (depends on 1) The PhC all-optical D-type flip-flop of claim 1, wherein said optical switch unit is a 2×2 optical selector switch, including a clock control signal CP, a first signal-input end, a second signal-input end, a first intermediate signal-output end and a second intermediate signal-output end; said first signal-input end is system signal-input end; said second signal-input end is reference-light input end. ### Claim 6 (depends on 2) The PhC all-optical D-type flip-flop of claim 2, wherein a cross section of the high-refractive-index linear-dielectric pillar of said 2D PhC is circular, elliptic, triangular or polygonal. ### Claim 7 (depends on 3) The PhC all-optical D-type flip-flop of claim 3, wherein said dielectric pillar in the quasi-1D PhC of said cross waveguide has a refractive index of 3.4 or a different value more than 2. ### Claim 8 (depends on 3) The PhC all-optical D-type flip-flop of claim 3, wherein the cross ection of said central dielectric pillar is square, polygonal, circular or elliptic. ### Claim 9 (depends on 3) The PhC all-optical D-type flip-flop of claim 3, wherein the cross section of said dielectric pillar in the quasi-1D PhC of said cross waveguide is rectangular, polygonal circular or elliptic. ### Claim 10 (depends on 1) The PhC all-optical D-type flip-flop of claim 1, wherein a background filling material for said 2D PhC includes air or a different low-refractive-index dielectric having a refractive index less than 1.4.