Compare Model Drawings, CAD & Specs Availability Price
Fast Steering Mirror System, 1 in. Removable Mirrors, ER.1 Coating
In Stock
In Stock
Fast Steering Mirror System, 1 in. Removable Mirrors, ER.4 Coating
3 Weeks
3 Weeks
Fast Steering System, 1 in. No Mirror
5 Weeks
5 Weeks


  • Angular Range
    ±1.5° (mechanical)
  • Reflectivity
    Enhanced Aluminum: > 93%, 450-700 nm
    Protected Gold: > 96%, 650-1700 nm; > 98%, 1.7-2 µm
  • Surface Quality
    15-5 scratch-dig
  • Surface Flatness
  • Resolution
    ≤1µrad rms (mechanical)
  • Repeatability
    ≤3µrad rms (mechanical)
  • Accuracy
    ≤0.262mrad rms (mechanical)
  • Maximum Power Exposure
    30 W peak, 15 W continuous
  • Cable Length
    3 m
  • Power Requirements
    100-240 Vac ±10%, 47-63 Hz
  • Operating Temperature Range
    Head: 0 to 50°C
    Controller: 0 to 35°C
  • Storage Temperature Range
    -20 to 55°C
  • Dimensions
    100 x 229 x 254 mm (h x w x d; controller)
  • Weight
    434 g (head)
    2.5kg (controller)


Table-to-Table Beam Stabilization System

Fast Steering Mirrors are commonly used in active beam stabilization systems to compensate for laser beam drift or to stabilize a beam passing from one optical table to another. This video deomnstrates an active beam stabilization system using all Newport components.

FSM vs. Galvanometers

Fast Steering Mirrors offer a more compact package with a unique flexure suspension design used to constrain the motion of the mirror, eliminating bearings with their associated stiction and wear common to XY galvanometers. FSMs eliminate the need to compensate for beam displacement and polarization rotation due to a second reflection. With higher optical performance than galvo scanners, FSMs have larger apertures, lower wavefront distortion, and a broader choice of mirror substrates and coatings. The rotational axes of an FSM intersect at a single pivot point, unlike dual XY galvos, eliminating the displacement jitter and the Pincushion Distortion.

Fast and Accurate Mirror Control

Four voice coil actuators provide fast, high-bandwidth rotation. Utilized in push-pull pairs, the actuators provide smooth, even torque to the mirror. An internal optical-based feedback loop is built into the FSM-300 head to provide position feedback with reference to the support frame for accurate and stable pointing and tracking. When used in combination with Newport’s OBP Series Laser Beam Position Sensing Detector, an FSM can quickly lock to the detector for rapid laser beam control and stabilization.

Gain Response for Small-Angle Excitation

Phase Response for Small-Angle Excitation

Enhanced Aluminum VIS-NIR Coating

The mirror of the FSM-300-01 system is coated with enhanced aluminum. Newport's ER.1 coating may be used wherever a broadband visible and near infrared reflector is needed. A multilayer dielectric stack deposited over the aluminum film boosts reflectance and improves the durability of the coating. Average reflectivity is > 93% from 450-700 nm.

Protected Gold NIR-IR Coating

The mirror of the FSM-300-02 system is coated with protected gold. Newport's ER.4 is ideal for applications requiring broadband reflectance in the near IR to the far IR. A multilayer dielectric overcoat provides protection to the gold from the environment. Average reflectivity is > 96% from 650 – 1700 nm and > 98% from 1.7 – 2.0 µm.

Field Replaceable Mirrors

Newport offers a standard FSM-300 system with a 1-in. (25.4-mm) diameter mirror installed. Other field-replaceable 1-in. mirror assemblies allow the user to field replace the standard mirror with another mirror that best fits the specific application. These additional replacement mirrors are available for different wavelengths ranging from 250 nm to 20 µm.

Easy Analog Interface

The FSM-CD300 controller provides a convenient interface between the user and the mirror, allowing analog control voltages to be applied and mirror position to be monitored. The controller incorporates independent gain and DC offset adjustments of both X and Y-axes. This enhancement significantly improves the system performance for Laser Pointing applications, requiring accurately controlled point-to-point movements.

Versatile and Economical

The FSM is an economical option for widespread commercial use for applications such as laser beam stabilization, laser pointing, tracking, and image stabilization.