Beam propagation method for step-index waveguides
AssigneeLucent Technologies Inc.
InventorChristopher Richard Doerr
Life of this patent
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Abstract
A method and apparatus are disclosed for simulating planar waveguides having a rectangular cross-section using a beam propagation method and design tool based on the FFT-BPM. Constraining the beam propagation method to planar waveguides having rectangular cross-sections significantly reduces the computational complexity and increases accuracy. The beam propagation method can be performed entirely in the angular spectrum domain. The constrained shape of the waveguide allows the structure to be accurately specified by its width and center-to-center arm spacing, thereby avoiding transverse spatial quantization.
Claims18
A beam propagation method for analyzing a lightwave propagation through a simulated planar lightwave circuit, said method comprising the steps of:
- defining a starting field that represents said lightwave;
- representing said propagation of said lightwave in free space by multiplying by a phase term in an angular spectrum domain;
- representing a guiding function of said lightwave in a region of said planar lightwave circuit having a refractive index distribution by convolving with impulse functions in an angular spectrum domain;
- and
- repeating each of said representing steps for each of a plurality of forward propagation increments.
A beam propagation method for analyzing a lightwave propagation through a simulated planar lightwave circuit, said method comprising the steps of:
- defining a structure of said planar lightwave circuit in an angular spectrum domain;
- and
- analyzing said lightwave propagation through a simulated planar lightwave circuit entirely in said angular spectrum domain.
A beam propagation method for analyzing a lightwave propagation through a simulated planar lightwave circuit, said method comprising the steps of:
- defining a structure of said planar lightwave circuit in an angular spectrum domain;
- and
- analyzing said lightwave propagation in an angular spectrum domain at a plurality of steps along a length of said simulated planar lightwave circuit by dispersing an angular spectrum of said lightwave to represent said propagation of said lightwave in free space and convolving said angular spectrum with a Fourier transform of a spatial index distribution to represent a guiding function of said lightwave in a region of said planar lightwave circuit having a refractive index.
A system for analyzing a lightwave propagation through a simulated planar lightwave circuit, said system comprising:
- a memory that stores computer-readable code;
- and
- a processor operatively coupled to said memory, said processor configured to implement said computer-readable code, said computer-readable code configured to:
- define a starting field that represents said lightwave;
- represent said propagation of said lightwave in free space by multiplying by a phase term in an angular spectrum domain;
- represent a guiding function of said lightwave in a region of said planar lightwave circuit having a refractive index distribution by convolving impulse functions in an angular spectrum domain;
- and
- repeat each of said representations for each of a plurality of forward propagation increments.
A system for analyzing a lightwave propagation through a simulated planar lightwave circuit, said system comprising:
- a memory that stores computer-readable code;
- and
- a processor operatively coupled to said memory, said processor configured to implement said computer-readable code, said computer-readable code configured to:
- define a structure of said planar lightwave circuit in an angular spectrum domain;
- and
- analyze said lightwave propagation through a simulated planar lightwave circuit entirely in said angular spectrum domain.
A system for analyzing a lightwave propagation through a simulated planar lightwave circuit, said system comprising:
- a memory that stores computer-readable code;
- and
- a processor operatively coupled to said memory, said processor configured to implement said computer-readable code, said computer-readable code configured to:
- define a structure of said planar lightwave circuit in an angular spectrum domain;
- and
- analyze said lightwave propagation in an angular spectrum domain at a plurality of steps along a length of said simulated planar lightwave circuit by dispersing an angular spectrum of said lightwave to represent said propagation of said lightwave in free space and convolving said angular spectrum with a Fourier transform of a spatial index distribution to represent a guiding function of said lightwave in a region of said planar lightwave circuit having a refractive index.
Dependencies are inferred from the claim text.