Large-aperture, low-inertia SiC beam steering, from long-range LIDAR to deep-space laser links. MERSEN optoSiC fast steering mirrors offer the highest combination of thermal and mechanical stability. Where MEMS mirrors hit their aperture ceiling, our FSM keep the beam precise, stable and on target.
Space-qualified: NASA’s Psyche mission
THE CHALLENGE
Why aerospace and long-range sensing outgrow a millimetre-scale mirror
MEMS mirrors do the job for automotive, near-field LIDAR at apertures of a few millimetres. Aerospace and long-range sensing are a different problem. You need a larger aperture to collect enough signal, dimensional stability across temperature swings that automotive parts never see, and a steering optic that holds its figure under vibration and vacuum.
This is where optoSiC silicon carbide fast steering mirrors shine. Low mass keeps your resonant frequency high and your response fast. High thermal conductivity and low expansion keep the surface flat in environments that are anything but stable.
HOW IT WORKS
A fast steering mirror tilts a single mirror on two axes to point or scan a beam. It uses closed-loop actuation to hold a commanded angle or follow a trajectory, with position feedback correcting drift in real time. optoSiCÂ supplies the SiC mirror and its monolithic mount.
Two things set the envelope: the mirror’s mass and its stiffness. A lighter, stiffer mirror reaches a higher resonant frequency, so it responds faster and settles sooner. Silicon carbide gives you both at once (low density and high specific stiffness), which is why an optoSiC FSM can carry a large aperture and still steer quickly. The nature-inspired backside rib removes mass without giving up flatness, so the reflecting surface stays true under acceleration.
WHY SiC
Apertures from 15.5 mm to 300 mm let you steer the beam sizes long-range and aerospace sensing actually need, not the 1–7 mm ceiling of MEMS. Bigger aperture means stronger return signals and more range - using the same laser, all without switching to a fragile, exotic substrate.
SiC's low density and our nature-inspired rib design lower overall moment of inertia. This way, your tip-tilt actuation stays fast and your resonant frequency stays high. Faster response and shorter settling let you scan more points per second or hold a tighter lock. The mirror keeps up with your control loop instead of limiting it.
High thermal conductivity (130 W/m·K, close to aluminium) and a very low coefficient of thermal expansion (2.5 ppm/K) hold the surface figure through temperature swings, vibration, and vacuum, with no outgassing (TML 0.01 %). Where glass or silicon would bow under thermal load and walk your beam off target, SiC stays flat, so the same optic survives from factory to orbit.
Application-matched ScanCoat stacks keep reflectivity high and absorption low - across the sensing and communication band, from 1030 and 1064 nm fibre wavelengths to the low-stress ScanCoat 1550-H (1530–1580 nm) for optical sensing and free-space links. Dual-band and custom stacks are available. Tell us your wavelength and AOI and we'll match the coating.
HOW IT WORKS
Bigger aperture, more return signal: range scales with the square root of the aperture area. Range is a signal-budget problem. The larger the mirror aperture, the more return signal you collect, and detection range scales with roughly the square root of the aperture area.
A millimetre-scale MEMS mirror runs out of photons at long range; a large aperture fast steering mirror keeps return signals strong enough to map, range, and profile farther, all with the same laser. Silicon carbide is what makes that aperture practical: light and stiff, so a 15.5–300 mm mirror steers fast and holds its figure, keeping the spot tight.
At long range, the mirror substrate decides whether your beam returns with a strong enough signal. MEMS mirrors are built for near-field, millimetre-scale scanning and cannot open up the aperture that aerospace and long-range sensing need. optoSiC fast steering mirrors provide that aperture with the thermal and mechanical stability MEMS cannot reach, and the flight heritage to prove it.
For near-field automotive, MEMS is fine. Any applications that demand higher precision standards, function in harsher environments reliably, SiC FSM is the way to go.Â
APPLICATIONS
Large aperture beam steering for LIDAR is mainly a signal-budget winner. A larger aperture collects more return light, so you can map, range, and profile at distances where a millimetre-scale mirror runs out of photons.
Tip-tilt steering holds pointing precise while the aircraft or satellite moves and SiC’s stiffness keeps the beam from blurring under platform vibration. From airborne survey and altimetry to atmospheric LIDAR, the mirror stops being the limit.
APPLICATIONS
Surveillance and reconnaissance optics have to work perfectly, every time. Shock on launch or take-off, wide temperature swings, and no maintenance window for the life of the mission. Silicon carbide SiC holds its surface figure across all of it, with no outgassing in vacuum, so your imagery and data stay clean from the first pass to the last.
APPLICATIONS
An optical link only closes if the beam stays locked on a moving receiver, often to sub-microradian accuracy across thousands of kilometres. That demands a steering mirror whose figure and pointing do not wander with temperature. SiC delivers it, and has proven it at the hardest distance there is: deep space.
APPLICATIONS
Mobile mapping, geodetic survey, and industrial metrology need repeatable pointing over long duty cycles. A low-inertia SiC mirrors settle fast and almost don’t drift – scan after scan lands where you expect, and throughput stays high.
Also fielded in: image and beam stabilisation, camera and telescope pointing, laser tracking and designation, embedded electro-optic systems on aircraft, UAVs, and satellites
PRODUCT RANGE
optoSiC builds fast steering mirrors in five series so you can size the optic to your system instead of designing around a fixed form factor. optoSiC+ silicon carbide is designed for a proprietary monolithic mount and manufactured for lowest mass and moment of inertia at its aperture. Standard parts ship from stock; custom geometries, mounts, and coatings are built to order.
Low mass and low moment of inertia, no compromises. optoSiC FSMs let your actuator reach a higher bandwidth at any given aperture.
optoSiC+ silicon carbide holds the highest figure of merit of any optically polishable material except diamond, and flexes less under acceleration than beryllium. It is a non-toxic, RoHS/REACH-conform beryllium replacement, and every mirror is laser-marked for full traceability.
Low mass and low moment of inertia are the point: they are what let your actuator reach a higher bandwidth at a given aperture. Full model-by-model tables (thickness, optical-axis height, coatings) can be found in the brochure and on the product page.
PRODUCT OVERVIEW
Against the alternatives it steers, that combination is why optoSiC+ has the highest figure of merit of any optically polishable material short of diamond, and why a SiC mirror deforms less under acceleration than beryllium.
A non-toxic beryllium replacement, fully traceable. SiC drops beryllium’s toxic-handling burden (RoHS and REACH conform) while giving higher dynamic stiffness and easier, lower-stress coating. Every optoSiC mirror is quality-controlled in three stages, post-sinter micro-crack inspection, post-polish metrology and interferometry, and post-coating environmental and adhesion tests, and is laser-marked with a unique ID for full traceability.
SPECIFY YOUR PROJECT
With your requirements in hand, our engineers recommend the right mirror, mount and coating for the job. Backed by over 20 years of design experience in SiC scanning optics, from stock apertures to custom and space-qualified builds, we look forward to helping your project reach its full potential.
Tilt angle and bandwidth are properties of your actuated system, not the bare mirror. We size the SiC optic and mount for the lowest inertia, so your actuator can reach the tilt and bandwidth your design demands.
Superior Optics for Accuracy and Speed
SiC scanning mirrors from optoSiC serve multiple laser-driven industries. If your application extends beyond laser material processing, explore our dedicated pillar pages:
Flight-proven beam steering for laser comms and space instruments
Fast steering mirrors (FSMs) precisely tip and tilt a beam to point, scan, or stabilise it. In LIDAR and sensing they steer the outgoing beam and track the return, enabling mapping, altimetry, ISR, and free-space optical links where a larger aperture and high pointing stability matter.
optoSiC supplies the high-performance SiC mirror and its monolithic mount, engineered for low mass and low moment of inertia. You drive it with your own actuator and controller, or your integration partner’s. Because the mirror sets the inertia, a lighter, stiffer SiC optic lets that actuator reach a higher bandwidth.
MEMS mirrors are limited to small apertures (around 1–7 mm), which suits short-range automotive LIDAR. optoSiC SiC FSMs offer apertures from 15.5 mm to 300 mm with the thermal and mechanical stability that long-range, aerospace, and space sensing require, plus flight heritage MEMS cannot match.
optoSiC FSMs span 15.5 mm to 300 mm across five series (FSM-T, FSM-3, FSM-4, FSM-R, FSM-RT), with mass from a few grams and correspondingly low moment of inertia. Standard parts ship from stock; custom apertures, mounts, and coatings are built to order.
Yes. optoSiC FSMs were used on NASA’s Psyche mission for deep-space laser communication across nearly half a billion kilometres, and optoSiC shares space-optics heritage with MERSEN Boostec.
Application-matched ScanCoat coatings cover the sensing and communication band, including low-stress 1550 nm coatings for optical sensing and communication. Specify your wavelength and angle of incidence for a recommendation.
Silicon carbide combines high thermal conductivity with a low coefficient of thermal expansion, so the mirror holds its surface figure across temperature swings and vibration, with no outgassing in vacuum.
Range is a signal-budget problem: a larger mirror aperture collects more return light, and detection range scales with roughly the square root of the aperture area. Millimetre-scale MEMS mirrors run out of photons at long range; a large-aperture SiC fast steering mirror keeps the return signal strong enough to map and range farther with the same laser.
Standard parts ship from stock. Custom FSM apertures and coatings are built to order, with lead time provided on request based on your specification.
In 2024, NASA’s Psyche spacecraft beamed a laser signal to Earth from nearly half a billion kilometres away (about 460 million km) – the most distant optical communication ever achieved. Steering that link with the precision it demands is an optoSiC silicon carbide (SiC) fast steering mirror. We offer these optics for the most demanding beam-pointing on Earth and in space.
NASA’s Deep Space Optical Communications (DSOC) experiment keeps its beam on target through a point-ahead fine-steering mechanism built around an optoSiC SiC mirror.
“Fine steering mirror based on piezo actuators: a point-ahead mechanism (PAM30) for the deep space optical communication module of the Psyche mission”
Authors: S. Hugi et al. — CEDRAT Technologies · ICSO 2020 / SPIE Proc. 11852 (2021)
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