Features

• 2-Axis Steering (Pitch and Yaw)
• >±24.0° Optical Angular Range
• Compact Mirror Housing
• Enables Easy Design of Optical Scanning Systems
• Calibrated Linear Response
• Digital Closed-Loop PID Feedback
• Software and Hardware Triggering Capabilities
• Designed for OEM and Research Applications

The FSM20XY Fast-Steering Mirror is a customer-inspired, high-performance 2D steering mirror designed to be integrated into custom-built systems. With an optical angular scan range in excess of ±24.0° and a clear aperture of Ø20 mm, the mirror is ideal for a variety of applications including general-purpose beam steering, auto-alignment systems, remote beam control, and image capture. Each mirror is calibrated so that the position of the mirror relative to the flat face of the mirror housing can be commanded by an SPI or UART electrical interface and software command set.

Design
The FSM20XY mirror has a protected silver coating on a polished metal substrate, which offers a reflectivity in excess of 95% throughout the 450 nm to 20 μm wavelength range. The mirror is supported by a frictionless flexure bearing support frame and is actuated using four voice coil actuators.

Integration
The compact mirror head includes four threaded holes for mounted. The included controller is built on a printed circuit board, which can be easily integrated into OEM applications. The OEM circuit board needs an external power supply that can provide +15 VDC at 3 A, -15 VDC at 3 A, and +7 VDC at 1.5 A. An optional enclosure with integrated power supply is also available for standalone and laboratory use of the FSM20XY.

Performance
Control of the fast-steering mirror is accomplished with the included digital Proportional Integral Derivative (PID) controller. From the initiation of the move command to the mirror settling at the final position, the fast-steering mirror can steer a beam through an angle of 48° in less than 60 ms. For a smaller 10° move, the settling time is less than 15 ms. For the fastest point-to-point execution times, the move or move sequence can be programmed into the 400 point FIFO queue in the controller. In addition, the trajectory profile and settling band can be custom tailored to meet the needs of a specific application or sequence of moves.

The position of the mirror is optically encoded using a position sensor that provides feedback to the PID control circuit. As a result, the mirror can be positioned with an accuracy of 1 mrad and repeatedly returned to the same position with an accuracy better than 1 mrad.

Since the mirror steers the beam in both the X and Y directions, pincushion distortion is minimized when compared to galvo-based scanning approaches. XY steering mirrors are also easy to incorporate into 2D scanning and imaging systems, since the mirror can be precisely positioned in a pupil plane.