FSO Instruments specializes in making advanced optical systems for laser satellite communication, both in ground stations and satellites. These ‘optical benches’ are optomechatronic masterpieces that transmit and receive laser signals with high accuracy. Under the Resolite brand name, we offer several models, labelled with a number that refers to the diameter of the aperture in millimeters.
FSM 20D
Fast Steering mirror for precision pointing of laser beams for free space optical communication
Details
- A compact and space compatible device with high compensation bandwidth and fast dynamical response;
- Custom reluctance actuators supporting superior device efficiency
- Flexural bearing yielding high linearity and no wear;
- Highly accurate angular feedback control through optional displacement sensors
- Successor of the space flight proven Demcon Focal FSM 20B, with extended optical range and ready for volume manufacturing
Technical properties
| Specification | Value |
|---|---|
| Physical properties | |
| Size (envelope) | Ø24 x 30.5mm (excl. mounting interface) |
| Weight bare FSM | 49g ± 5g |
| Weight sensors | 17g |
| Tip/tilt performance | |
| Tip/tilt range (circular) | Mechanical: ±2° Optical: ±2° |
| Tip/tilt resonances | 135 Hz (nominal) |
| Pointing jitter | <1.5 μrads (optical) @1.7 kHz control bandwidth |
| Optical properties | |
| Mirror aperture diameter | Mechanical: 21.5mm Optical: 18mm (guaranteed performance) |
| Optical coating | Protected Gold (other coatings possible) 97% reflectivity @ 1550nm |
| Surface form error | < 22 nm RMS for all operational load cases defined |
| Electrical properties | |
| Number of actuation channels | 4 channels |
| Coil properties | Resistance: 4.8 Ω ±10% Inductrance: 3.75 mH ±10% (TBC) |
| Cable harness | 8 wires for actuation 4 wires for angular sensors 2 wires for temperature sensors |
| Sensitivity | 0.13 rad/A |
Resolite-20 optical head
Designed for Direct to earth (DTE) in Low Earth Orbit (LEO) at 500 to 1000km
Details
- Asymmetric connection: 1Gbps transmit, 200kbps receive.
- Resolite 20 is part of the terminal brought to market by AAC Clyde Space
- Available now
Technical properties
| Parameter | Value |
|---|---|
| Targeted Use Case | Direct to Earth |
| Aperture Diameter | 17 mm |
| Volume (LxWxH) | 1U (96x96x96) mm3 |
| Mass | 1.3 kg |
| Power | 15 W |
| Link Distance (@ max data rate) | 1000 km |
| Data rate Transmit | 1 Gbps |
| Data rate Receive | 200 kbps |
| Wavelength band | 1545-1590 nm RMS |
| FoR – Azimuth | +/-0.35 deg |
| FoV | Satellite pointing |
| FoR – Elevation | Satellite pointing |
| Lifetime | >4 years |
| Available on the market | 2024 |
Resolite-50 optical head
Designed for Data Relay from a LEO satellite into a LEO constellation
Details
- Asymmetric connection Optical InterSatellite Link: 2.5Gbps transmit, 300Mbps receive
- Resolite-50 will be available in 2026, first flight planned for H1 2027
- Also capable of Direct to Earth (DTE) connections
Technical properties
| Parameter | Value |
|---|---|
| Targeted use Case | ISL – Data relay |
| Aperture Diameter | 50 mm |
| Volume (LxWxH) | 5U mm3 |
| Mass | 4 kg |
| Power | 75 W |
| Link Distance (@ max data rate) | 5000 km |
| Data rate Transmit | 2.5 Gbps |
| Data rate Receive | 0.3 Gbps |
| Wavelength band | C-band (SDA) |
| FoV | +/-0.3 deg |
| FoR – Azimuth | +/-170 deg |
| FoR – Elevation | -35 – +85 deg |
| Lifetime | >5 years |
| Available on the market | 2026 |
Resolite-80 optical head
Optical InterSatellite Link optical bench for communication constellations in LEO orbit
Details
- Symmetric connection: 100Gbps transmit, 100Gbps receive
- Resolite 80 will be available in 2026
Technical properties
| Parameter | Value |
|---|---|
| Targeted use Case | ISL – High speed bidirectional constellations |
| Aperture Diameter | 80 mm |
| Volume (LxWxH) | 250x250x320 mm3 |
| Mass | 15 kg |
| Power | 75 W |
| Link Distance (@ max data rate) | 5500 km |
| Data rate Transmit | 100 Gbps (OOK, D-QPSK) |
| Data rate Receive | 100 Gbps (OOK, D-QPSK) |
| Wavelength band | C-band (SDA) |
| FoV | +/-0.25 deg |
| FoR – Azimuth | +/-170 deg |
| FoR – Elevation | -35 – +85 deg |
| Lifetime | >6 years |
| Available on the market | 2026 |