The Application Gallery features COMSOL Multiphysics® tutorial and demo app files pertinent to the electrical, structural, acoustics, fluid, heat, and chemical disciplines. You can use these examples as a starting point for your own simulation work by downloading the tutorial model or demo app file and its accompanying instructions.

Search for tutorials and apps relevant to your area of expertise via the Quick Search feature. To download the MPH-files, log in or create a COMSOL Access account that is associated with a valid COMSOL license. Note that many of the examples featured here can also be accessed via the Application Libraries that are built into the COMSOL Multiphysics® software and available from the File menu.

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Directional Coupler

Two embedded optical waveguides in close proximity form a directional coupler. The cladding material is GaAs and the core material is ion-implanted GaAs. The waveguide is excited by the two first supermodes of the waveguide structure - the symmetric and antisymmetric modes. Two numeric ports are used on both the exciting boundary and the absorbing boundary, to define the two modes. A boundary ...

Fabry-Perot Cavity

This is an example of a Fabry-Perot cavity, the simplest optical resonator structure. It is a classical problem in optics and photonics. Two methods are shown for computing the Q-factor. The losses in this model are purely via radiation away from the resonator.

Stress-Optical Effects with Generalized Plane Strain

Planar photonic waveguides in silica (SiO2) have great potential for use in wavelength routing applications. The major problem with this type of waveguide is birefringence. Anisotropic refractive indices result in fundamental mode splitting and pulse broadening. The goal is to minimize birefringence effects by adapting materials and manufacturing processes. One source of birefringence is the use ...

Time-Domain Modeling of Dispersive Drude-Lorentz Media (Wave Optics)

This tutorial shows how to solve the full time-dependent wave equation in dispersive media such as plasmas and semiconductors. The 2D TM in-plane wave model solves for the vector potential from the wave equation and for an auxiliary electric polarization density from an ordinary differential equation. The geometry consists of a single dispersive slab with a sub-wavelength slit in it. Periodic ...

Self-Focusing

A Gaussian beam is launched into BK-7 optical glass. The material has an intensity-dependent refractive index. At the center of the beam, the refractive index is the largest. The induced refractive index profile counteracts diffraction and actually focuses the beam. Self-focusing is important in the design of high-power laser systems. The model demonstrates 3D nonlinear wave propagation.

Step-Index Fiber Bend

The first part of the application computes the modes for a straight step index fiber made of silica glass. In the second part, a step index fiber bend with a 3 mm radius of curvature is analyzed with respect to propagating modes and radiation loss. It is shown how to find the power averaged mode radius and how to use this to compute the effective mode index.

Computing the Scattering of Light from a Rough Surface with a Metal Coating

These examples demonstrate how to compute the total reflection, transmission, and absorption of light when a plane wave, at optical wavelengths, is incident upon a dielectric slab with a thin metal coating. Three examples are included that show: 1. An optically flat slab 2. A slab with a sinusoidal variation in height 3. A slab with random roughness These model files relate to the blog ...

Second Harmonic Generation of a Gaussian Beam (Wave Optics)

It is possible to generate harmonics that are multiples of the frequency of laser light by using nonlinear optical materials. This model demonstrates second harmonic generation using transient wave simulation and nonlinear material properties. A YAG (lambda=1.06 micron) laser beam is focused on a nonlinear crystal so that the waist of the beam is inside the crystal.

Gaussian Beam Incident at the Brewster Angle

This model demonstrates the polarization properties for a Gaussian beam incident at an interface between two media at the Brewster angle. The model shows how to use the Electromagnetic Waves, Beam Envelopes physics interface with a User defined phase specification. Matched Boundary Condition features are used for absorbing waves incident to boundaries at non-normal directions.

Multipole Analysis of Electromagnetic Scattering

The multipole expansion is a powerful tool for analyzing electromagnetic waves scattered by small objects. In the expansion, the scattered field is represented as a superposition of the fields created by a finite set of point multipoles. Each point multipole is connected to a unique electric current mode in the object. This connection can be harnessed to design scatterers with prescribed ...