Knowledge

How to choose optical simulation software?

The market for optical and photonic simulation software offers dozens of tools. The right choice depends on the scale of your system, the purpose of the simulation and the design stage — and also on how the tool fits into your process: from CAD integration to the licensing model and support. This guide walks through each of these criteria in turn.

Methods for modelling optical phenomena: ray tracing, FDTD, BPM, EME

Modelling optical phenomena is the numerical reproduction of light propagation and its interaction with matter — from macroscopic lens systems to photonic nanostructures. There is no single method that works everywhere: the choice between ray tracing and full electrodynamics decides the accuracy, the computational cost, and which effects you will even see in the result. This guide organises the methods — ray tracing, FDTD, BPM, EME, mode solver, RCWA and system simulation — and shows when to reach for which.

What is ray tracing? Applications in optical engineering

Ray tracing is one of the fundamental methods for simulating light propagation. Used both in 3D rendering and in professional engineering software, it lets you predict how light will behave in a designed optical system before it is built. In this article we explain how it works, how engineering ray tracing differs from graphics ray tracing, and where it is used in practice.

Photonics in industry: simulation and design

Photonics increasingly ends up inside industrial devices and systems: fiber links, sensors, optoelectronic circuits, and photonic integrated circuits (PIC). Designing a single component is not enough — you have to check its behaviour at the level of the photonic structure, the optical-electronic circuit, and the whole system. This guide organises the photonic design process and shows how to match the method — mode analysis, BPM, FDTD, circuit simulation, or system simulation — to the level of the problem.

How does the FDTD method work, and when should you use it? A guide to photonic simulation

FDTD (Finite-Difference Time-Domain) is one of the most important numerical methods for modelling light propagation and the interaction of electromagnetic waves with photonic structures. It solves Maxwell's equations directly in the time and space domain, so it can analyse phenomena that geometrical optics alone cannot describe reliably — from waveguides and resonators to photonic crystals and diffractive elements. This guide explains how FDTD simulation works, how to prepare a model, and when to reach for this method instead of BPM or mode analysis.

What is stray light and why does it matter? A guide to scattered-light analysis

Stray light, or unwanted light, is radiation that reaches a place where it should not be — a detector or an image plane by a path other than the designed optical path. In imaging systems it lowers contrast and image quality, in detection systems it raises the background and worsens the signal-to-noise ratio, and in laser systems it creates additional power-propagation paths. This guide explains where stray light comes from, why it is a problem for the whole opto-mechanical assembly, and how it is analysed with non-sequential ray tracing.

PIC : the photonic integrated circuit. What is it and which tools are used to design it?

A Photonic Integrated Circuit (PIC) is the photonic counterpart of an integrated circuit — instead of transistors and electrical connections, it integrates on a single substrate the elements responsible for guiding, splitting, combining, modulating, filtering, and detecting light. The idea itself is simple; the difficulty starts with design, because the geometry of the device is directly tied to its optical properties. That is why designing a PIC is not one simulation task, but a chain of models at different levels of detail. This guide shows which Optiwave and Lambda Research program handles which level.

Optimising optical systems: best practices

Designing an optical system rarely ends with finding a solution that simply „works”. We want it to work as well as possible — high transmission, adequate bandwidth, low loss, the right spectral response, low aberration, high tolerance to parameter changes and, in production, manufacturability with a given process. This leads to the next stage of working with simulation: we not only simulate the system, but use the simulation to optimise it. And good optimisation does not start by running an algorithm — it starts by correctly defining the problem.

How is a fiber-optic link simulated? From the transmitter to BER

Simulating an optical link does not start at the fiber and does not end with checking whether light appears at the output. Information passes through the whole chain: from the data generator, through the transmitter and modulation, the fiber and intermediate elements, to the receiver, where the signal is turned back into data. A system-level simulation builds a model from connected blocks — transmitter, fiber, amplifiers, filters, receiver — and checks the effect the whole path has on transmission quality. This guide shows how it works: from bits, through the eye diagram and Q-factor, to BER.

Automating photonic measurements: OptiInstrument

In a photonics lab, running a single measurement is rarely the hardest part. What gets difficult is running the same measurement reliably hundreds or thousands of times, across different wavelengths, power levels, temperatures, driving voltages or device configurations. That is exactly where instrument automation comes in.

Software for fiber design — from the refractive-index profile to a complete system

An optical fiber can look, at first glance, like a simple element: a core, a cladding, and light guided over long distances. From a designer's point of view, though, it is a wave structure whose geometric and material parameters determine its modes, dispersion, loss, birefringence, polarization, effective mode area, and susceptibility to nonlinear effects. That is why there is no single, universal "fiber software" — within the Optiwave ecosystem, the central tool for designing the fiber itself is OptiFiber.

Designing optical sensors for industry

An optical sensor is a far more complex system than the phrase "light source plus photodetector" suggests. How it behaves can depend on propagation in a waveguide, changes in refractive index, resonance, reflection from a Bragg grating, scattering, absorption, lens geometry, stray light, and the readout electronics. That is why sensor design is such a good illustration of why photonics relies on several different kinds of simulation.

Designing LiDAR systems for autonomous platforms

LiDAR is one of the most demanding examples of an optical system. It has to emit a controlled laser beam, steer it into space, collect the tiny fraction of light reflected from an object, separate the useful signal from background, and determine distance from the timing or another property of the signal. In autonomous systems, on top of that come sunlight, glare from other vehicles and infrastructure, contamination, vibration, tight packaging constraints, and a very low level of light returning to the receiver.

Simulating optoelectronic circuits in OptiSPICE

Electronics and photonics are increasingly ceasing to be separate parts of a device. A laser is driven by an electronic circuit, a photodiode works together with a transimpedance amplifier, a modulator receives an electrical signal, and the whole circuit can include feedback loops that cross between the optical and electrical domains. In that case, simulating the optics separately from the electronics may not be enough.

Analysing loss in optical fibers with OptiFiber

Loss is one of the basic parameters of any fiber-optic path. In a transmission system it is most often described by an attenuation coefficient in dB/km, but that simplification isn't always enough when designing the fiber itself. The designer isn't only interested in "how much power will be left after 10 kilometres?", but also in why the fiber loses power and how changing its geometry affects that loss.

Case studies

Glossary

Optical and photonic simulation terms — ray tracing, FDTD, BPM, silicon photonics, fiber-optic telecom.