# US 2014/0153078 A1 · Simulation method for an optical modulator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153078 A1 - Document ID: US20140153078A1 - Status: Published application - Kind: A1 - Application number: 14/084,702 - Filed: 2013-11-20 - Published: 2014-06-05 - Earliest claimed: 2012-11-30 - Assignees: STMicroelectronics S.r.l. - Applicants: Stmicroelectronics SA - Inventors: Jean-Robert MANOUVRIER - Web page: https://patentgrep.com/patent/US20140153078A1 ## CPC - G02F 1/015: based on semiconductor elements having potential barriers, e.g. having a PN or PIN junction (G02F1/03 takes precedence) - G02F 1/025: in an optical waveguide structure (G02F1/017, {G02F1/2257} take precedence) - G02F 1/2257: {the optical waveguides being made of semiconducting material} - 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 ## Abstract A simulation model is for an optical modulator that may include an optical phase shifter in a semiconductor material structure between two sections of an optical waveguide. The semiconductor material structure may include one of a P-N and P-I-N junction in a plane parallel to an axis of the optical waveguide. The model may include a diode configured to characterize an electrical behavior of the one of the P-N and P-I-N junction such that a change in a global refractive index of the optical phase shifter is expressed, by a coefficient, based upon an amount of charges in the one of the P-N and P-I-N junctions and raised to a power. The coefficient and the power may be empirical values based upon the semiconductor material and a wavelength. ## Claims ### Claim at position 1 1-9. (canceled) ### Claim 10 A simulation model for an optical modulator comprising an optical phase shifter comprising a semiconductor material structure to be coupled between two sections of an optical waveguide, the semiconductor material structure having a junction in a plane parallel to a longitudinal axis of the optical waveguide, the simulation model comprising: a diode model configured to characterize an electrical behavior of the junction such that a change in a global refractive index of the optical phase shifter is expressed, by a coefficient, based upon an amount of charges in the junction, and raised to a power, the coefficient and the power being empirical values based upon the semiconductor material and a wavelength. ### Claim 11 (depends on 10) The simulation model according to claim 10, wherein said diode model is configured to characterize the electrical behavior of the junction such that the change in a global refractive index of the optical phase shifter is expressed, by a coefficient, proportional to the amount of charges in the junction, and raised to a power. ### Claim 12 (depends on 10) The simulation model according to claim 10, wherein the global refractive index comprises a refractive index indicative of overall behavior of the optical phase shifter. ### Claim 13 (depends on 10) The simulation model according to claim 10, wherein the junction comprises one a P-N and P-I-N junction. ### Claim 14 (depends on 10) The simulation model according to claim 10, wherein said diode model is configured to characterize a reverse-bias operation thereof, and wherein the amount of charges comprises an amount of depletion charges in the junction. ### Claim 15 (depends on 10) The simulation model according to claim 10, wherein said diode model is configured to characterize a forward-bias operation thereof, and wherein the amount of charges comprises an amount of injection charges in the junction. ### Claim 16 (depends on 10) The simulation model according to claim 10, wherein the change in the global refractive index comprises a sum of a depletion component proportional, by a first coefficient, to an amount of depletion charges in the junction, raised to a first power, and an injection component, proportional by a second coefficient, to an amount of injection charges in the junction, raised to a second power. ### Claim 17 (depends on 10) The simulation model according to claim 10, wherein a change in a absorption coefficient of the optical phase shifter comprises a sum of a depletion component, proportional by a third coefficient, to an amount of depletion charges in the junction, raised to a third power, and an injection component, proportional by a fourth coefficient, to an amount of injection charges in the junction, raised to a fourth power; and wherein the third and fourth coefficients, and third and fourth powers comprise empirical values based upon the semiconductor material and the wavelength. ### Claim 18 A simulation method for an optical modulator comprising an optical phase shifter comprising a semiconductor material structure to be coupled between two sections of an optical waveguide, the semiconductor material structure having a junction, the method comprising: characterizing electrical behavior of the junction by at least determining an amount of charges in the junction, and expressing a change in a global refractive index of the optical phase shifter with a coefficient based upon a power of the amount of charges, wherein the coefficient and the power are based upon at least one of the semiconductor material and a wavelength. ### Claim 19 (depends on 18) The method according to claim 18, wherein the change in the global refractive index is expressed with a coefficient proportional to the power of the amount of charges. ### Claim 20 (depends on 18) The method according to claim 18, wherein the global refractive index comprises a refractive index indicative of overall behavior of the optical phase shifter. ### Claim 21 (depends on 18) The method according to claim 18, wherein characterizing the electrical behavior comprises characterizing a reverse-bias operation, and wherein the amount of charges comprises an amount of depletion charges in the junction. ### Claim 22 (depends on 18) The method according to claim 18, wherein characterizing the electrical behavior comprises characterizing a forward-bias operation, and wherein the amount of charges comprises an amount of injection charges in the junction. ### Claim 23 (depends on 18) The method according to claim 18, wherein determining the amount of charges in the junction comprises determining an amount of depletion charges in the junction, and determining an amount of injection charges in the junction; and wherein expressing the change in the refractive index comprises expressing the change in the refractive index as a linear combination of the amounts of depletion charges and injection charges raised to respective powers. ### Claim 24 A simulation method for an optical modulator comprising an optical phase shifter comprising a semiconductor material structure to be coupled between two sections of an optical waveguide, the semiconductor material structure having a junction in a plane parallel to a longitudinal axis of the optical waveguide, the method comprising: characterizing electrical behavior of the junction by at least determining an amount of charges in the junction, and expressing a change in a refractive index of the optical phase shifter with a coefficient based upon a power of the amount of charges, wherein the coefficient and the power are based upon the semiconductor material and a wavelength. ### Claim 25 (depends on 24) The method according to claim 24, wherein the change in the refractive index is expressed with a coefficient proportional to the power of the amount of charges. ### Claim 26 (depends on 24) The method according to claim 24, wherein characterizing the electrical behavior comprises characterizing a reverse-bias operation, and wherein the amount of charges comprises an amount of depletion charges in the junction. ### Claim 27 (depends on 24) The method according to claim 24, wherein characterizing the electrical behavior comprises characterizing a forward-bias operation, and wherein the amount of charges comprises an amount of injection charges in the junction. ### Claim 28 (depends on 24) The method according to claim 24, wherein determining the amount of charges in the junction comprises determining an amount of depletion charges in the junction, and determining an amount of injection charges in the junction; and wherein expressing the change in the refractive index comprises expressing the change in the refractive index as a linear combination of the amounts of depletion charges and injection charges raised to respective powers.