Modern optical systems are expected to do more than simply direct light from point A to point B. Free-space optical communication (FSOC) systems must maintain stable links despite vibration, atmospheric disturbances, and platform movement, while advanced imaging systems are expected to cover increasingly larger areas without sacrificing resolution.
Meeting these requirements demands optical components that can actively adapt to changing conditions in real time.
At Optotune, this challenge is at the core of what we do. Since 2008, we have developed adaptive optical components that combine precision optics with innovative actuation technologies, enabling engineers to build more responsive, compact, and high-performance optical systems. Our portfolio includes focus tunable liquid lenses, beam steering devices, beam shifting devices, and laser speckle reducers used across medical, industrial, and consumer markets.
Among these technologies, 2D fast steering mirrors have emerged as a powerful solution for dynamic beam control. In this article, we explore how fast steering mirrors work, the challenges they help solve, and how Optotune’s beam steering portfolio supports applications ranging from FSOC to gigapixel imaging, machine vision, and industrial inspection.
The Growing Need for Optical Beam Steering
Optical beam steering refers to controlling the direction of an optical beam with high precision. Depending on the application, beam steering may be used to compensate for vibration, track moving objects, stabilize communication links, scan large areas, or redirect a camera toward a specific region of interest.
When selecting a beam steering technology, engineers typically evaluate several key parameters:
- Angular range
- Bandwidth and speed
- Resolution
- Repeatability
- Accuracy
- Supported beam size
No single steering technology optimizes all of these parameters simultaneously. Instead, system designers must select the solution that best matches the requirements of their application
Optotune's Beam Steering Portfolio
Optotune offers multiple technologies for optical beam steering, allowing engineers to choose the most suitable approach for their optical architecture.
For systems that require large steering angles and rapid dynamic positioning, Optotune’s 2D fast steering mirrors provide optical steering angles of up to ±50° while supporting applications across visible, SWIR, and infrared wavelengths. For in-line optical systems where a folded optical path is undesirable, Optotune also offers liquid prism technology that enables beam steering in transmission.
Our current beam steering portfolio includes solutions optimized for a variety of operating points:
MR-15-30
A large-angle 2D steering mirror capable of ±25° mechanical tilt on both axes, corresponding to an optical field of view of up to 100°. This makes it particularly attractive for coarse steering and imaging applications requiring wide coverage.
MR-13×15 Series
Designed for higher bandwidth and precision positioning, making it suitable for fine steering and disturbance compensation applications such as FSOC beam stabilization.
FMR-20
A high-bandwidth fast steering mirror platform intended for applications requiring small steering angles but very rapid response.
Together, these solutions enable engineers to cover everything from coarse pointing over large fields of view to high-speed correction of optical disturbances.
Why Fast Steering Mirrors?
Many optical systems rely on galvanometer scanners to achieve two-dimensional beam steering. While effective, this approach typically requires two mirrors positioned sequentially in the optical path.
This architecture introduces several compromises. Beam shift must often be compensated through calibration, the optical assembly becomes larger because the second mirror needs to accommodate the redirected beam, and two reflective surfaces introduce additional optical loss.
Optotune’s 2D mirror architecture takes a different approach. Steering occurs on a single reflective surface, with the point of rotation located close to the mirror itself. The result is a compact design with minimal beam shift and only a single reflection loss.
For system designers, this can simplify integration while improving optical efficiency.
Inside an Optotune Fast Steering Mirror
At the heart of Optotune’s steering mirrors is a combination of precision mechanics, closed-loop control, and integrated position sensing.
The mirrors use a moving-magnet actuation architecture combined with a long-lifetime precision bearing. Optical position sensors continuously monitor mirror orientation, allowing the system to maintain accurate positioning under dynamic conditions. Calibration data is stored directly within the device, simplifying system integration and controller pairing.
This architecture provides several benefits:
- Accurate closed-loop positioning
- Compact package size
- High repeatability
- Efficient thermal management
- Robust mechanical reliability
- Long operational lifetime
Different mirror coatings are available depending on wavelength requirements, supporting applications ranging from visible imaging to infrared communication systems.
Designed for Harsh Environments
Optical systems deployed outside a laboratory environment must tolerate temperature variations, mechanical shock, vibration, and years of continuous operation.
Several design decisions contribute to the robustness of Optotune’s steering mirrors. The center of mass is aligned with the center of rotation, reducing the torque induced by external vibration. A restoring magnetic force helps return the mirror to its neutral position, while closed-loop PID control can actively compensate for disturbances.
To validate performance under real-world conditions, Optotune performs extensive environmental testing, including temperature cycling, temperature shock, vibration testing, mechanical shock testing, free-fall testing, and accelerated lifetime evaluations. Long-term testing has also demonstrated operation over billions of cycles.
For engineers building mission-critical optical systems, reliability is often just as important as performance specifications.
Free-Space Optical Communication: The Need for Active Stabilization
Free-space optical communication transfers data through a highly collimated optical beam travelling through open air. Often described as “fiber in the air,” FSOC offers fiber-like bandwidth without requiring physical fiber infrastructure.
The technology is gaining momentum across applications that include:
- Building-to-building communication
- Satellite communication
- Drone networks
- Airborne platforms
- Remote connectivity
However, maintaining a stable optical link is not trivial. Weather conditions, platform vibration, tower sway, atmospheric turbulence, and pointing errors can all affect link performance. Because communication beams are intentionally narrow, even small angular deviations can significantly reduce received power.
This is where fast steering mirrors become critical.
How Optotune Supports FSOC Systems
Most FSOC terminal designs use a dual-stage architecture.
A coarse steering stage manages large angular movements measured in degrees, while a fine steering stage compensates for smaller disturbances at significantly higher speeds.
Optotune’s beam steering portfolio aligns naturally with this architecture.
The MR-15-30, with its large steering range and optical field of view of up to 100°, is well suited for coarse steering applications. The MR-13×15 platform provides the bandwidth and precision required for fine steering and disturbance rejection. Together, these technologies allow engineers to combine large pointing range with high-speed correction.
This combination can be particularly attractive for systems operating on moving platforms or in environments where vibration cannot be avoided.
Demonstrated Optical Link Stabilization
To evaluate the performance of fast steering mirrors in an FSOC scenario, Optotune constructed a demonstration system featuring a 532 nm laser, a mechanically induced 34 Hz disturbance, and an MR-13×15 steering mirror operating in a closed-loop configuration. The stabilization loop ran at 4 kHz.
The setup compared two optical receivers:
- One without active stabilization
- One with stabilization provided by the steering mirror
The stabilized link exhibited reduced beam jitter and significantly lower oscillation amplitudes compared with the unstabilized configuration. According to the demonstrated results, disturbance rejection of approximately 13 dB was achieved for disturbances corresponding to pointing errors up to 85 µrad.
These results highlight how active beam steering can improve communication link stability under mechanically disturbed conditions.
Beyond Communication: Large-Field-of-View Imaging
While communication is one important application area, beam steering technology is equally valuable in advanced imaging systems.
Traditional imaging architectures force a compromise between coverage and detail. Wide-angle optics provide scene awareness but sacrifice resolution. Telephoto optics deliver detail but observe only a small portion of the environment.
Optotune’s fast steering mirrors enable a different approach.
By directing a narrow-field optical path to multiple locations across a scene, a single imaging system can capture detailed information from a much larger area. Images can then be stitched into gigapixel composites or used to inspect specific areas of interest.
How Field-of-View Expansion Works
Field-of-view expansion combines optical steering with camera calibration and image processing.
The process begins by calibrating camera distortion, transforming coordinate systems between the mirror and the target plane, and compensating for image rotation introduced by steering. Mirror positions are carefully selected so that images acquired across the scene align properly when stitched together.
The result is a system capable of observing a much larger area than a static telephoto camera while maintaining significantly higher image detail than a wide-angle lens alone.
For surveillance, inspection, and industrial automation applications, this can dramatically reduce the number of cameras required to monitor a large area.
Real-World Applications Enabled by Optotune
Optotune’s beam steering technologies are already supporting a range of demanding imaging and machine vision applications.
High-Speed Barcode Reading
Steerable optical systems can rapidly shift between different targets across a large field of view while maintaining high resolution. This approach enables barcode reading and logistics applications that would otherwise require multiple cameras.
Pallet Inspection and Warehouse Automation
The combination of fast steering mirrors and adaptive optics allows imaging systems to scan large pallet areas from relatively short working distances while maintaining detailed image quality.
PCB and Semiconductor Inspection
Field-of-view expansion allows engineers to inspect specific regions of electronic assemblies while working at short distances and preserving image resolution.
Security and Surveillance
Wide-area monitoring systems can combine scene awareness and detailed inspection by pairing wide-angle cameras with steerable telephoto optical paths. Applications include public-space monitoring, face tracking, and drone detection.
Gigapixel Imaging
By acquiring hundreds or thousands of narrow-field images and stitching them together, steering mirrors can support extremely high-resolution composite images covering large areas. The gigapixel Zurich demonstration presented by Optotune illustrates this capability.
Proven in Customer Applications
Beyond laboratory demonstrations, Optotune technologies have also been incorporated into customer and partner solutions.
Toyo Electric Corporation demonstrated a 40 Gbps free-space optical communication system utilizing Optotune’s MR-15-30 steering mirror. In imaging and security applications, companies such as Cognex and Wamda.ai have implemented steering-mirror-based approaches for barcode reading, field-of-view expansion, and large-area surveillance concepts.
These examples demonstrate the versatility of adaptive beam steering across communication, industrial, and imaging applications.
How Optotune Enables Adaptive Optical Systems
Optical systems are becoming increasingly dynamic. Communication links must adapt to disturbance. Imaging systems must observe larger areas without sacrificing detail. Machine vision systems must respond to changing targets in real time.
Optotune’s adaptive optics portfolio is designed to meet these challenges.
Our 2D fast steering mirrors provide beam steering and stabilization for communication and imaging systems. Our focus tunable liquid lenses enable rapid electronic focus adjustment. Liquid prism technology supports compact in-line beam steering, while complementary adaptive optical technologies address a wide range of optical control challenges.
By combining optics with innovative actuation technologies, Optotune helps engineers develop systems that are faster, more flexible, more compact, and better able to respond to the real world.
Interested in exploring fast steering mirror technology for your application? Contact the Optotune team to discuss your requirements or explore our beam steering portfolio.
