7 results about "Propagation constant" patented technology

A high-conversion-efficiency integrated frequency comb device (100; 200; 310a – 310c) comprises at least one micro-resonator (120; 220) configured to receive pump laser light from at least one pump laser source, convert at least partially the received pump laser light for generating a laser frequency comb, and output frequency comb light based on the produced laser frequency comb. The micro-resonator (120; 220) comprises at least one closed-circuit waveguide (122; 222) integrated in a semi-conductor topography of the micro-resonator (120; 220). The closed-circuit waveguide (122; 222) comprises at least one structure for producing periodic perturbation (124; 224) configured to produce mode hybridization via coupling of forwards and backwards travelling modes in the closed-circuit waveguide (122; 222) by means of rapid, in particular sub-wavelength, modulation of a propagation constant of light propagating in the closed-circuit waveguide (122; 222). The structure for producing periodic perturbation (124; 224) has been designed with respect to at least one of an intended width, in terms of comb lines, of the frequency comb and / or an intended intensity distribution within a target width, in terms of comb lines, of the frequency comb, based at least partially on the stipulation that a dispersion-loss operator to achieve an ideally flat microcomb according to an exact solution of a generalized Lugiato-Lefever Equation exists in the form [iD+K], and, as a function of resonator mode index μ, the dispersion-loss operator takes the following generic form: wherein a, b, c, d 3 ... d ∞ , h, p, q, r, s, u 3 , u ∞ are constants, and μ ≤ N / 2 for N being the number of intended comb lines apart from a potential comb line corresponding to the pump laser light.

Embodiments of the present application provide a lithium niobate dispersion compensation method, system, device and storage medium, belonging to the technical field of integrated photonics. The method comprises: obtaining the mode effective refractive index of the target lithium niobate waveguide in a preset frequency spectrum range, and calculating the corresponding propagation constant based on the mode effective refractive index to construct a mode dispersion function; calculating the phase mismatch parameter corresponding to each frequency point based on the mode dispersion function, and constructing a frequency domain phase mismatch distribution function based on the phase mismatch parameter of each frequency point; generating a phase compensation amount corresponding to each frequency point based on the frequency domain phase mismatch distribution function; generating a modulation control parameter based on the phase compensation amount, and applying it to the lithium niobate waveguide to achieve dispersion compensation. The present application scheme realizes continuous compensation of phase mismatch of each frequency component in a wide frequency range, and changes the phase matching from local effectiveness to consistency in the whole frequency domain.

This invention discloses an on-chip optical phased array device based on phase change materials and its control method. The device includes an input waveguide, a beam splitter network, arrayed waveguide arms, a phase modulation unit, and an output grating radiation structure. The output grating radiation structure integrates a phase change material. Changes in the phase state, crystallinity, or spatial distribution of the phase change material are used to alter the equivalent refractive index, propagation constant, radiative coupling strength, or phase matching conditions of the output grating region, thereby achieving second-dimensional output angle adjustment at a fixed operating wavelength. This invention not only eliminates the dependence on tunable lasers but also possesses advantages such as simplified structure, ease of integration, non-volatile state preservation, zero static power consumption, and greater suitability for engineering implementation. It provides a new implementation path for on-chip two-dimensional optical phased arrays and has good application value and promising prospects for widespread application.

This invention discloses a method for measuring the electromagnetic wave propagation constant of an electromagnetic structure. Based on the field values ​​at three equally spaced points, this invention uses analytical expressions incorporating these three field values ​​to represent the phase constant and attenuation constant of a one-dimensional homogeneous or periodic structure. This method is simple, fast, and accurate. It can be applied to both homogeneous and periodic structures; both closed transmission line structures such as waveguides and open transmission lines such as microstrip lines; both waveguide structures of transmission lines and radiating structures of antennas; and both lossless and lossy structures.

The application discloses a two-port radio frequency device de-embedding method, calculates the characteristic impedance and propagation constant of the transmission line corresponding to the section of the port through a two-dimensional section solver; calculates the equivalent electromagnetic wave wavelength at the port according to the propagation constant; modifies the original layout, and expands the port outward by a length of half the wavelength; sets an excitation at the port of the expanded layout, and obtains the scattering parameters of the layout corresponding to the device at the moment through simulation by the method of moments; and through matrix operation, the influence of the added transmission line is stripped, the scattering parameters of the original layout corresponding to the device are obtained, and the de-embedding process is completed. The application also discloses a device, an electronic equipment and a storage medium based on the method. The application can effectively strip the influence of the lumped excitation source on the scattering parameters of the radio frequency device in the simulation process of the method of moments, so that the simulation result is more accurate.

The present invention aims to provide a mode conversion device and a design method thereof, which can design arbitrary coupling efficiency and full width at half maximum. The present invention is a mode conversion device having a long-period grating in a core of an optical fiber capable of propagating light in at least two propagation modes, characterized in that the long-period grating satisfies a relationship of mathematical formula C1. Wherein, the full width at half maximum FWHM is a wavelength band in which the coupling efficiency is half compared to the coupling efficiency of the mode conversion of the center wavelength, C is the coupling efficiency, L c is the full coupling length, L g is the grating length, Λ is the grating pitch, and Δβ is the difference in propagation constant of the two propagation modes of the center wavelength as a target of mode conversion; [Mathematical formula C1]

The application discloses a method for measuring electromagnetic wave propagation constant of two-dimensional periodic structure. The method is based on field values of five points in the structure, and uses an analytical expression containing the field values of the five points to respectively express phase constants and attenuation constants of two dimensions of the two-dimensional periodic structure. The method is simple, fast and accurate. The method can be used for two-dimensional uniform structure, two-dimensional periodic structure, closed transmission line structure, open transmission line, two-dimensional waveguide structure, antenna radiation structure, non-loss structure and loss structure.