FastSteering Mirrors

F S M S E R I E S

The Fast Steering Mirror Series provides two-axis, high-bandwidth rotation with sub-microradian mechanical resolutionusing voice-coil technology. Utilizing a unique flexuresuspension design to confine the motion of the mirror results inultra-smooth motion about a gimbal point, very high accuracy,and practically no wear. Newport offers a wide range of 1" fieldreplaceable mirrors.

Versatile and Economical

The FSM is an economical option for widespread commercialuse for applications such as laser beam stabilization, laserpointing, tracking, and image stabilization.

FSM vs. Galvanometers

Fast Steering Mirrors offer a more compact package with aunique flexure suspension design used to constrain the motionof the mirror, eliminating bearings with their associated stictionand wear common to XY galvanometers. FSMs eliminate theneed to compensate for beam displacement and polarizationrotation due to a second reflection. With higher opticalperformance than galvo scanners, FSMs have larger apertures,lower wavefront distortion, and a broader choice of mirrorsubstrates and coatings. The rotational axes of an FSM intersectat a single pivot point, unlike dual XY galvos, eliminating thedisplacement jitter and the Pincushion Distortion.

Field Replaceable Mirrors

Newport offers a standard FSM-300 with a 1” (25.4 mm)diameter mirror. A wide range of replaceable 1” mirrorassemblies allows the user to field replace the standard mirrorwith another mirror that best fits the specific application. Theseadditional standard mirrors are available for different wavelengthranging from 250–1700 nm.

• Fast steering on a single pivot point for X and Y rotation

• Steering mirror is suspended on a flexure, eliminating friction

• Angular range ±3° and resolution ≤2 µrad rms, optical

• Fast closed-loop control, to 580 Hz

• Field replaceable 1 in. mirror assemblies

• Larger angular range than piezo-driven mirrors

• Eliminates displacement jitter found in dual XY galvo mirror systems

Fast and Accurate Mirror Control

Four voice coil actuators provide fast, high-bandwidthrotation. Utilized in push-pull pairs, the actuators providesmooth, even torque to the mirror. An internal optical-based feedback loop is built into the FSM-300 head toprovide position feedback with reference to the supportframe for accurate and stable pointing and tracking. Whenused in combination with Newport’s OBP Series LaserBeam Position Sensing Detector, an FSM can quickly lockto the detector for rapid laser beam control andstabilization.

Easy Analog Interface

The FSM-CD300 controller provides a convenient interfacebetween the user and the mirror, allowing analog controlvoltages to be applied and mirror position to be monitored.The controller incorporates independent gain and DCoffset adjustments of both X and Y-axes. Thisenhancement significantly improves the systemperformance for Laser Pointing applications, requiringaccurately controlled point-to-point movements.

FSM SERIES

Mirror AssemblyNumber of Axes 2 (tip-tilt)

Angular Range from ±10 V (mrad) ±26.2 (±1.5°), Mechanical (1)

Resolution, rms (µrad) ≤1, Mechanical (1)

Repeatability, rms (µrad) ≤3, Mechanical (1)

Accuracy from ±26.2 mrad, 25 °C(1) (mrad) ≤0.262 (0.015°), Mechanical (1)

Linearity from ±26.2 mrad, 25 °C(1) ≤1.0%

Closed-Loop Amplitude Bandwidth for small signal inputs (-3 dB) 580 Hz at 10 mV (typical)

Closed-Loop Phase Bandwidth (60° lag) 250 Hz (typical)

Response Flatness(2) Peaking ≤3 dB

Noise Equivalent Angle ≤3 µrad rms

Resolution of Local Position Sensor (µrad) ≤0.5

Operating Temperature Range 0 to 50 °C (32 to 122 °F)

Storage Temperature Range -20 to 55 °C (-4 to 131 °F)

Sensor Warm-up Time for Mirror Stability at 25 °C ≤10 minutes

Mass 1lb (0.45 kg)

Interconnect Cable Length 9.8 ft (3 m)

Dialectric Mirror Substrate Material Pyrex

Mirror Retaining Mechanism Mirror bonded to aluminum carrier, field replaceable

Pivot Point of Axes (centered on mirror) 12.19 mm behind mirror surface

Mirror Diameter 25.4 mm

Mirror Thickness 6.0 mm

Mirror Wedge ≤5 arc-min

Clear Aperture (at 0° angle of incidence) ≥20.3 mm

Clear Aperture (at 45° angle of incidence) ≥14.4 mm

Reflectivity (2) Enhanced Aluminum: >93%, 450–700 nm

Protected Gold: >96%, 650–1700 nm; >98%, 1.7–2.0 µm

Surface Flatness (2) (after coating and bonding) ≤λ/8 at 632.8 nm over clear aperture

Surface Quality (2) 15-5 scratch-dig

1) Optical angular range is equal to twice the mechanical angular range.2) Optical parameters apply to central 80% of mirror aperture.

Controller/DriverCommand Input and Position Output Analog, ±10 V yields ±26.2 mrad

Peak Operating Power to Mirror (W) 30

Continuous Maximum Operating Power to Mirror (W) 15

Thermal Protection 60 °C at mirror coil

Current Protection 3 A

Operating Temperature Range 0 to 50 °C (32 to 122 °F)

Storage Temperature Range -20 to 55 °C (-4 to 131 °F)

Power 100–240 Vac ±10%, 47–63 Hz

Mass 5.45 lb (2.5 kg)

Envelope, w x h x d [in (mm)] 9 x 3.45 x 10 (229 x 88 x 254)

Note: Performance data is based upon well-defined, smooth, D-A sine wave inputs. Contact Newport regarding alternateinputs (square waves, triangle waves, low resolution D-A sine waves), which may adversely effect systemperformance.

S P E C I F I C A T I O N S

F A S T S T E E R I N G M I R R O R S

Frequency (Hz)

Mag

nitu

de (d

B)

-11-10-9-8-7-6-5-4-3-2-1012

1 10 100 1000 10000

3 dB point

Typical Gain Response for Small-Angle Excitation

Note: Amplitude is 0.262 mrad

60 degreepoint

Frequency (Hz)

Phas

e La

g (d

egre

es)

-180-170-160-150-140-130-120-110-100-90-80-70-60-50-40-30-20-10

010

1 10 100 1000 10000

Typical Phase Response for Small-Angle Excitation

Note: Amplitude is 0.262 mrad

Frequency (Hz)

Mag

nitu

de (d

B)

-8

-7

-6

-5

-4

-3

-2

-1

0

1

10 100 1000 10000

FSM 300-3 dB

Typical Gain Response for Small-Angle Excitation

Frequency (Hz)

10 100 1000 10000

FSM 30060 Degree Phase Lag

Typical Phase Response for Small-Angle Excitation

Phas

e La

g (d

egre

es)

-180-170-160-150-140-130-120-110-100-90-80-70-60-50-40-30-20-10

010

Bode Plots for Typical FSM

Command Amplitude (mrad)

Freq

uenc

y (H

z)

0.01

0.1

1

10

100

FSM 300

Typical Safe Operating Area

0 40 50 150 250 350 450 550 650650 750 850 950

Typical Operating Area for FSM

Newport Corporation, Irvine, California and Franklin, Massachusetts; Evry and Beaune-la-Rolande, France and Wuxi, China have all been certified compliant with ISO 9001 by the British Standards Institution. Santa Clara, California is DNV certified.

Complete listings for all global office locations are available online at www.newport.com/contact

www.newport.comNewport Corporation, Global Headquarters1791 Deere Avenue, Irvine, CA 92606, USA

PHONE: 1-800-222-6440 1-949-863-3144 FAX: 1-949-253-1680 EMAIL: sales@newport.com

PHONE EMAIL

PHONE EMAILK

FSM SERIES FA S T S T E E R I N G M I R R O R S

FSM

_DSE

(01/

16)

D I M E N S I O N S

CLEAR APERTURE>ø0.80 (20mm)

DIELECTRICMIRROR

1.50(38.1)

1.25(31.7)

1.12(28.6)

4.09(103.8)

2.50(63.5)

1.42(36)

2.13(54)

3.25(82.6)

3.50(88.9)

.13(3.2)

.71(18.1)

2.13(54)

2.25(57.2)

5X ø9/32 (7.14mm)HOLES FOR ø1/4 (M6)MOUNTING SCREWS

3.79(96.2)

.25(6.4)

2.24(56.8)

.38(9.5)

.66(16.6)

2.63(66.7)

2.26(57.3) 15 PIN CONNECTOR

4X #4-40 SCREWSATTACH BASE TO FSM

1.53(38.7)

.50(12.7)

1.04(26.3)

1.25(31.8)

FSM-300 Series

O R D E R I N G I N F O R M A T I O N

Model Description

FSM-300-01 Fast Steering Mirror System, 1 in. Removable Mirrors, ER.1 Coating

FSM-300-02 Fast Steering Mirror System, 1 in. Removable Mirrors, ER.4 Coating

FSM-300-NM Fast Steering System with 1 in. Mirror Fixture

FSM-K1 Fast Steering Mirror, 1 in. 1 kHz

FSM-K1-NM Fast Steering Mirror, 1 in. 1 kHz, No Mirror