DEV Community: Martynas Adomaitis

From Code to Beam: How Software and Optics Work Together in Industrial Laser Systems

Martynas Adomaitis — Mon, 14 Sep 2026 10:22:31 +0000

A modern industrial laser system is as much a software system as it is an optical one.

Software defines power, pulse timing, scan paths, positioning, and process parameters. Sensors feed data back into the control stack, while algorithms can adjust the process as the machine runs.

But the workpiece never sees the value your software requested.

It sees the laser beam that actually arrives after passing through mirrors, filters, lenses, windows, scanners, and other components in the optical path.

That distinction matters when debugging laser systems.

A process that appears to be a control problem can sometimes be an optical problem. Better software cannot always compensate for what happens at the physical layer.

From Software Command to Laser Beam

A simplified industrial laser system might look like this:

Process Recipe / CAD Data 
↓
Control Software
↓
Laser Controller
↓
Laser Source
↓
Beam Delivery Optics
↓
Workpiece
↓
Sensors / Monitoring
↓
Feedback Logic
↺

The software specifies what should happen.

The optical system influences how much of that command actually reaches the process.

If the controller requests a certain laser power, losses, contamination, thermal drift, alignment, and coating performance can all affect the beam delivered to the target.

For developers working close to the hardware, it helps to think of optics as part of the system's physical layer.

What Does the Software Actually Control?

The exact control stack varies across laser systems, but several parameters are typically handled on the software side.

Laser Power and Pulse Timing

Software can command laser power, repetition rate, pulse timing, and sometimes pulse shape.

In pulsed systems, changes to timing can alter the amount and distribution of energy delivered to the process.

The controller knows what it requested. A monitoring system is needed if you also want to know what happened physically.

Motion and Beam Position

Laser processing systems often coordinate the laser with galvanometer scanners, stages, robots, or other motion hardware.

The software may need to synchronize:

position + velocity + laser power + pulse timing

A positioning error can produce the wrong process result, but so can a beam that has changed shape, focus, or alignment before it reaches the scanner.

Closed-Loop Control

More advanced systems use sensor data to adjust the process while it is running.

NIST researchers demonstrated a laser powder bed fusion system that could adjust laser power within approximately 118 microseconds of acquiring a melt-pool measurement. The correction could be made before the beam moved beyond the current melt pool.

That type of loop looks familiar from a software perspective:

Measure
↓
Compare with the target
↓
Calculate error
↓
Adjust actuator
↓
Measure again

The complexity is that the controlled system is a physical process in which optical, thermal, mechanical, and material behaviors occur simultaneously.

Where Optics Enter the Stack

Between the laser source and the target is usually an optical delivery system.

Different components perform different jobs.

Laser Mirrors

Mirrors steer the laser through the machine.

At high powers, they need to do more than provide high reflectivity. Absorption, laser-induced damage resistance, wavefront quality, angle of incidence, and thermal stability can all affect the beam that reaches the process.

Dichroic Mirrors and Filters

Not every wavelength follows the same route.

Dichroic mirrors can reflect one wavelength while transmitting another. This allows systems to combine beams, separate harmonics, inject pump light, or send monitoring wavelengths toward cameras and sensors.

This becomes particularly useful when the processing beam and monitoring system need to share part of the same optical path.

Polarizing Optics

Polarization can affect both laser-material interaction and the behavior of other optical components.

Polarizers, waveplates, and polarization-sensitive coatings can be used to control the polarization state before the beam reaches the process.

Windows and Lenses

Windows protect parts of the system, while lenses shape or focus the beam.

Their coatings matter too. Reflections that appear small as percentages can become meaningful losses as laser power increases.

Why the Coating Process Matters

Much of a laser optic’s performance comes from thin-film coatings applied to its surface.

High-reflectivity mirrors, dichroics, polarizers, filters, and anti-reflective optics commonly use stacks of dielectric layers. By controlling the material and thickness of each layer, optical engineers can influence which wavelengths are reflected or transmitted and how the optic affects polarization and dispersion.

Several deposition methods are used to manufacture these coatings. One is ion beam sputtering (IBS), a physical vapor deposition process in which an ion beam ejects material from a target before depositing it onto an optical substrate.

For developers, the important point is what coating performance means at the system level. Depending on the application, engineers may need to control:

Reflectivity
Transmission
Optical absorption
Spectral bandwidth
Laser-damage resistance
Polarization behavior
Dispersion
Batch-to-batch repeatability.

These characteristics define part of the physical operating envelope within which the control software must operate.

When an Optical Problem Looks Like a Software Bug

This is where things become interesting from a debugging perspective.

You can have perfectly valid control logic and still see the process drift.

Delivered Power Slowly Falls

Suppose your command remains:

laser_power = 500 W

But process performance gradually declines.

The obvious places to investigate might be the power supply, calibration data, or control algorithm.

But a contaminated, misaligned, or degrading optical component can also reduce the amount of usable power reaching the workpiece.

The requested value has not changed. The physical transfer function has.

Focus Changes During Operation

A process may work correctly at startup and gradually move out of specification.

One possible cause is thermal behavior in the optical system. Absorbed laser energy can heat an optic, altering its shape or changing the wavefront passing through it.

The software may see a stable command and stable stage position while the actual focal conditions change.

Monitoring Data Becomes Noisy

Sensors are not automatically ground truth.

The monitoring optics, detector bandwidth, calibration, and sampling architecture all affect what reaches the control algorithm.

NIST research into laser powder bed fusion found that phenomena such as spatter, plume formation, laser modulation, and melt-pool oscillations may require acquisition rates above 10 kHz. Those sampling requirements create a trade-off between temporal bandwidth and the spatial information available from monitoring sensors.

Single-point sensors such as photodiodes can capture fast signals, while imaging systems provide richer spatial information but generate much larger streams of data.

A control algorithm can only react to what its sensors can observe.

The Beam Is in the Right Place, but the Process Is Wrong

Position is only part of the beam delivery.

Wavefront distortion, changes in spot size, polarization, alignment, and spectral behavior can change the interaction with the material without producing an obvious motion-control error.

From the software layer, the machine may appear healthy.

From the workpiece's perspective, something has changed.

Building Better Feedback Loops

The lesson is not that developers need to become optical coating engineers.

It is that robust control systems need useful observability into the physical process.

Measure Output, Not Just Commands

A commanded value tells you what the controller intended.

Where practical, measure quantities closer to the actual process:

Commanded laser power
↓
Measured delivered power
↓
Process response

Comparing these layers makes it easier to determine where drift enters the system.

Combine Multiple Signals

A single sensor rarely describes the entire process.

Research into laser additive manufacturing increasingly combines optical, acoustic, thermal, and other sensing methods. A recent review identifies multimodal sensor fusion, machine-learning-assisted defect detection, and real-time closed-loop feedback control as key directions for moving toward adaptive, lower-defect manufacturing.

For a developer, this is essentially an observability problem.

The more useful state you can infer from the process, the better decisions the controller can make.

Track Drift Over Time

Not every failure is binary.

An optic can slowly become contaminated. Alignment can drift. Transmission can decline. Thermal behavior can change as components age.

Logging trends can expose these changes before they become hard failures.

Instead of only asking:

is_process_ok = true

The more useful questions may be:

how_fast_is_power_drifting?

has_focus_metric_changed?

is_sensor_baseline_moving?

did_the_change_start_after_maintenance?

This is where software can add significant value.

Know What Software Cannot Fix

Closed-loop control is powerful, but compensation has limits.

If a mirror has excessive absorption, a filter has the wrong spectral response, an optic is approaching its damage limit, or a coating introduces too much dispersion, continually adjusting software parameters treats the symptom rather than the cause.

Good automation depends on a physical system that remains within the operating envelope around which the controller was designed.

The Software Is Only as Good as the Physical System

Industrial laser machines increasingly behave like cyber-physical systems.

Software coordinates the process. Sensors describe what is happening. Algorithms calculate corrections. Hardware executes them.

But between the command and the result sits the physical optical system.

For developers, that creates a useful debugging principle:

requested state ≠ delivered state ≠ process state

When those three begin to diverge, the cause may lie in the control code, sensor pipeline, calibration, laser source, optics, or interactions among several layers.

The best systems make those layers observable enough to tell the difference.

Photonics vs Optics: What Developers and Engineers Should Know

Martynas Adomaitis — Tue, 28 Apr 2026 10:33:39 +0000

Optics is the broader study of how light behaves and interacts with matter. Photonics is a specialized branch of optics focused on using photons in technologies such as lasers, LEDs, fiber optics, sensors, and photonic circuits.

The two fields often overlap, but they are not the same. Optics is more about controlling light using components such as lenses, mirrors, prisms, and filters. Photonics is more about applying light-based technology in real systems, from LiDAR and fiber networks to medical devices, laser manufacturing, and optical sensors.

For developers and engineers, the distinction matters because software increasingly works with physical systems. Cameras, machine vision tools, LiDAR, fiber networks, and laser-based hardware all depend on optical and photonic components.

What Is Optics?

Optics is the study of the behavior and properties of light, including how light travels, reflects, refracts, focuses, scatters, and interacts with materials.

In practical terms, optics is the field behind many familiar components and systems, including:

Lenses
Mirrors
Prisms
Filters
Telescopes
Microscopes
Cameras
Spectacles
Imaging systems.

Classical optics often focuses on how light can be controlled using physical components. For example, a camera lens focuses light onto an image sensor. A microscope uses lenses to magnify tiny objects. A mirror redirects light. A prism bends and separates light into different wavelengths.

Optics also includes more advanced areas, such as physical and quantum optics, but the core idea is simple. It is about the behavior and control of light.

What Is Photonics?

Photonics is the science and technology of photons, which are particles of light. It focuses on technologies that generate, transmit, transform, detect, and manipulate light, including lasers, LEDs, fiber optics, sensors, and photonic circuits.

Common photonics technologies include:

Lasers
LEDs
Photodetectors
Fiber optic cables
Optical sensors
LiDAR systems
Solar cells
Photonic chips
Optical communication systems
Medical imaging devices
Laser manufacturing systems.

Photonics is especially important in modern technology because light can carry information, measure distance, detect changes, transmit data, generate energy, and process materials with high precision.

For example, fiber internet uses light signals to transmit data. In LiDAR systems, laser pulses are used to measure distance and build 3D images, while optical components help shape, direct, and collect the light.

Solar panels convert photons into electrical energy. Medical imaging systems use light to help detect and diagnose conditions.

Photonics vs Optics: The Key Differences

The easiest way to think about the difference is this:

Optics studies and controls light. Photonics uses photons as a technology platform.

Area	Optics	Photonics
Main focus	How light behaves and is controlled	How photons are generated, transmitted, detected, and used
Typical components	Lenses, mirrors, prisms, filters	Lasers, LEDs, detectors, fiber optics, photonic circuits
Common uses	Imaging, magnification, vision correction, beam shaping	Communications, sensing, LiDAR, laser processing, solar cells
Scale	Often macroscopic light control	Often micro-scale, electronic, or system-level light technology
Developer relevance	Cameras, machine vision, AR/VR, optical modelling	Optical networking, sensors, robotics, data acquisition, photonic computing

In reality, the two fields overlap all the time. A laser system, for example, is usually considered a photonics technology because it generates and manipulates photons. But it still depends on optical components such as lenses, mirrors, filters, beam splitters, and coatings to shape and control the beam.

Is Photonics a Branch of Optics?

Yes. Photonics is generally considered a specialized branch of optics.

Optics is the broader field. Photonics sits within that broader field and focuses more specifically on photon-based technologies and practical applications.

That is why the terms are sometimes used together in phrases like “optics and photonics”, “optical engineering”, and “photonic systems”. The distinction is useful, but the boundary is not always strict.

A simple way to separate them is:

Optics: How does light behave?
Photonics: How can we use photons to build technology?

Where Optics and Photonics Overlap

Many real-world systems rely on both optics and photonics.

Take a laser cutting system. The laser source itself is part of photonics because it generates a controlled beam of photons. But the system also needs optics to shape, direct, focus, reflect, and protect that beam.

The same is true in scientific, industrial, medical, and defense laser systems. A laser may be the photonics component, but the system's performance depends heavily on optical components such as mirrors, filters, beam splitters, lenses, windows, and coatings.

In high-power environments, optical components must withstand intense operating conditions. Standard components may fail because of absorption, coating degradation, thermal effects, or laser-induced damage. This is where specialist high-power laser optics become important, as factors such as laser-induced damage threshold, absorption, coating structure, pulse duration, repetition rate, and beam diameter can all affect long-term performance.

Examples of Optics and Photonics in Real Technology

The overlap becomes clearer when you look at everyday and industrial technologies.

Technology	Optics involved	Photonics involved
Smartphone camera	Lenses, filters, image formation	CMOS sensor detecting photons
Fiber internet	Light guidance through fiber	Lasers, modulation, signal detection
LiDAR	Beam shaping and light collection	Laser pulses, detectors, and time-of-flight measurement
Laser cutting	Mirrors, lenses, protective windows	High-power laser source and beam control
AR/VR headset	Lenses, waveguides, displays	MicroLEDs, sensors, optical tracking
Medical imaging	Lenses, scopes, filters	Lasers, detectors, optical sensors
Solar panels	Light collection and surface interaction	Photons converted into electrical energy
Machine vision	Camera optics and lighting	Sensors converting light into data

This is why developers working with hardware-adjacent systems often need at least a basic understanding of both fields.

Why Developers Should Care About Optics and Photonics

If you work with physical systems, sensors, cameras, robotics, data acquisition, or industrial automation, optics and photonics can affect the quality of the data your software receives.

For example, a machine vision model is only as good as the images captured by the camera system. Poor lighting, lens distortion, reflections, or sensor noise can create problems that look like software issues but actually start in the optical setup.

A robotics system using LiDAR depends on laser pulses, detectors, optics, calibration, and signal processing. If the optical alignment is wrong or the sensor is affected by environmental conditions, the software may receive noisy or unreliable data.

A fiber network depends on photonics to transmit and detect light signals, but it also depends on optical principles to guide that light through the fiber with minimal loss.

A laser manufacturing system may be controlled by software, but its reliability depends on the laser source, optical coatings, beam delivery components, thermal stability, and safety systems.

In other words, real-world systems are full-stack in the truest sense. The stack does not stop at the API, firmware, or sensor driver. It extends into physics, materials, light, heat, and mechanical tolerances.

Final Thoughts

Optics and photonics are closely related, but they are not interchangeable.

Optics is the broader study and engineering of light behavior. Photonics is the applied technology of photons, especially in systems that use lasers, LEDs, sensors, fiber optics, and photonic circuits.

For developers and engineers, the distinction is useful because more software now interacts with physical systems. Cameras, sensors, LiDAR, fiber networks, medical devices, manufacturing tools, and scientific instruments all depend on light-based technologies.

The more you understand the optical and photonic layers that underpin these systems, the easier it becomes to diagnose issues, communicate with hardware teams, and build products that perform reliably in the real world.