Fast Steering Mirrors

TECHNICAL REFERENCE AND
FUNDAMENTAL APPLICATIONS
LENS SELECTION GUIDE
SPHERICAL LENSES
CYLINDRICAL AND
SPECIALTY LENSES
OPTICS SETS
OPTICAL SYSTEMS
MIRRORS
508
FSM-300-01
Optics
Fast Steering Mirrors
Newport introduces the new FSM-300 Fast Steering Mirror. Our Fast Steering Mirror
(FSM) product offering provides two-axis, high-bandwidth rotation with sub-microradian
resolution. Newport offers standard designs that are economically viable for widespread
commercial use for applications such as laser beam stabilization, laser scanning, laser
pointing, tracking, and image stabilization.
By utilizing a unique flexure design to confine the motion of the mirror, the bearing
surfaces often used with galvanometer scanners are eliminated, along with their
associated stiction and wear. This results in ultra-smooth motion, very high accuracy, and
practically infinite lifetime.
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, scanning, and tracking. When used
in combination with Newport’s OBP Series Laser Beam Positioner, or a commercially
available quad cell, an FSM can quickly lock to the detector for rapid laser beam control
and stabilization.
The controller/driver establishes the feedback interface between the angle sensors and
the drivers, providing current to the voice coils that tip and tilt the mirror assembly. It
also provides a convenient interface between the user and the mirror, allowing control
voltages to be applied and mirror position to be monitored. The controller/driver
contains the control circuits, current drivers, universal power supply, and user interface.
The updated FSM-CD300 Series Controller incorporates upgraded firmware that allows for
independent gain and DC offset adjustments of both X and Y-axes. This enhancement
significantly improves the system performance for Laser Pointing applications such as
Raster Scanning, requiring accurately controlled point-to-point movements.
Fast Steering Mirrors offer a more compact package than dual XY galvometer scanners.
They eliminate the need to displace the beam to accommodate a second galvo or to
compensate for polarization rotation due to an extra 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.
Newport offers a standard FSM-300 with a 1” (25.4mm) diameter mirror. A wide range of
1” mirror assemblies (mirror on carrier) for the FSM-300 are offered. This allows the user
to field replace the standard mirror with another mirror that best fits the specific
application. 1" mirror assemblies are sold separately.
• Single pivot point for both X and Y rotation
• Flexure suspension eliminates friction
• Angular range ±3°, optical
• Angular resolution ≤2 µrad rms, optical
• Fast closed-loop control, to 800 Hz
• New field replaceable 1 in. mirror assemblies
• Larger angular range than piezo-driven mirrors
• Eliminates displacement jitter found in dual XY galvo
mirror systems
Applications
• Laser Beam Stabilization
• Laser Scanning
• Laser Pointing
• Tracking
• Image Stabilization
FSM-300 Mirror Assembly
Rear View of Mirror Assembly
Front panel of the FSM-300 controller/driver.
PRISMS
Back view of the FSM-300 controller/driver.
Phone: 1-800-222-6440 • Fax: 1-949-253-1680

Optics
509
Typical Specifications
Mirror Assembly
FSM-300-01
Number of Axes
2 (tip-tilt)
Angular Range from ±10 V ±26.2 mrad (±1.5°), Mechanical (1)
Resolution ≤1 µrad rms, Mechanical (1)
Repeatability ≤3 µrad rms, Mechanical (1)
Accuracy from ±26.2 mrad, 25°C (1) ≤0.262 mrad (0.015°), Mechanical (1)
Linearity from ±26.2 mrad, 25°C (1)
≤1.0%
Closed-Loop Amplitude Bandwidth for small signal inputs (-3 dB)
800 Hz at 10 mV (typical)
Closed-Loop Phase Bandwidth (60° lag)
400 Hz (typical)
Response Flatness (2)
Peaking ≤3 dB
Noise Equivalent Angle
≤3 µrad rms
Resolution of Local Position Sensor
≤0.5 µrad
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
TECHNICAL REFERENCE AND
FUNDAMENTAL APPLICATIONS
LENS SELECTION GUIDE SPHERICAL LENSES CYLINDRICAL AND
SPECIALTY LENSES
1) Optical angular range is equal to twice the mechanical angular range.
2) Optical parameters apply to central 80% of mirror aperture.
Controller/Driver
Command Input and Position Output
Peak Operating Power to Mirror
Continuous Maximum Operating Power to Mirror
Thermal Protection
Current Protection
Operating Temperature Range
Storage Temperature Range
Power
Mass
Envelope [w x h x d]
Analog, ±10 V = ±26.2 mrad
30 W
15 W
60°C at mirror coil
3 A
0 to 50°C (32 to 122°F)
-20 to 55°C (-4 to 131°F)
100-240 Vac ±10%, 47-63 Hz
5.45 lb (2.5 kg)
9 x 3.45 x 10 in. (229 x 88 x 254 mm)
Note: Performance data is based upon well-defined, smooth, D-A sine wave inputs. Contact Newport regarding
alternate inputs (square waves, triangle waves, low resolution D-A sine waves), which may adversely effect system
performance.
OPTICS SETS OPTICAL SYSTEMS MIRRORS PRISMS
Email: sales@newport.com • Web: newport.com

510
Optics
TECHNICAL REFERENCE AND
FUNDAMENTAL APPLICATIONS
LENS SELECTION GUIDE
Bode Plots for Typical FSM
Magnitude (dB)
1
0
-1
-2
-3
-4
-5
-6
-7
Typical Gain Response for Small-Angle Excitation
––– FSM 300
••••• -3 dB
Reflectance (%)
100
90
80
70
60
100
0°
ER.1
Enhanced Aluminum
0.4 0.6 0.8 2 4 6 8 10
Wavelength (µm)
0°
Typical
SPHERICAL LENSES
CYLINDRICAL AND
SPECIALTY LENSES
10
0
-10
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
-130
-140
-150
-160
-170
Magnitude (dB)
-8
10 100 1000 10000
Frequency (Hz)
Typical Phase Response for Small-Angle Excitation
-180
10 100
Frequency (Hz)
1000 10000
––– FSM 300
••••• 60 Degree Phrase Lag
OPTICS SETS
Typical Operating Area for FSM
100
Typical Safe Operating Area
OPTICAL SYSTEMS
Command Amplitude (mrad)
10
1
0.1
––– FSM 300
MIRRORS
0.01
0 40 50 150 250 350 450 550 650 750 850 950
Frequency (Hz)
Ordering Information
Model
FSM-300-01
FSM-300-02
Description
Fast Steering Mirror, 1in (25.4mm) Removable Mirrors, ER.1 Coating
Fast Steering Mirror, 1in (25.4mm) Removable Mirrors, ER.4 Coating
PRISMS
Typical
Reflectance (%)
90
80
70
60
ER.4
Protected Gold
0.4 0.6 0.8 2 4 6 8 10
Wavelength (µm)
Phone: 1-800-222-6440 • Fax: 1-949-253-1680

Optics
511
Spare Mirror Ordering Information
Model (Metric) Description Material Description, Extended
FSM-300-M-01 Spare Mirror Assy, FSM-300 Pyrex ® AL.2 Coating, UV Enhanced Aluminum, 250-600nm
FSM-300-M-02 Spare Mirror Assy., FSM-300 Pyrex ® ER.1 Coating, Enhanced Aluminum, 450-700nm
FSM-300-M-03 Spare Mirror Assy., FSM-300, Pyrex ® ER.2 Coating, Protective Silver, 480-1100nm
FSM-300-M-04 Spare Mirror Assy., FSM-300 Pyrex ® ER.4 Coating, Protective Gold, 650-1700nm
FSM-300-M-05 Spare Mirror Assy., FSM-300 Pyrex ® BD.1 Coating, Broadband Dielectric, Visible, 488-694nm
FSM-300-M-06 Spare Mirror Assy., FSM-300 Pyrex ® BD.2 Coating, Broadband Dielectric, Near-IR, 700-950nm
FSM-300-M-07 Spare Mirror Assy., FSM-300 Pyrex ® DM.6 Coating, Laser Line, HeCd, 441.6nm
FSM-300-M-08 Spare Mirror Assy., FSM-300 Pyrex ® DM.5 Coating, Laser Line, Argon-Ion, 488/514.5nm
FSM-300-M-09 Spare Mirror Assy., FSM-300 Pyrex ® DM.4 Coating, Laser Line, NeNe, 632.8nm
FSM-300-M-10 Spare Mirror Assy., FSM-300 Pyrex ® DM.10 Coating, Laser Line, Nd:YAG, 1064nm
FSM-300-M-11 Spare Mirror Assy., FSM-300 Pyrex ® DM.8 Coating, Laser Line, Diode, 1520-1580nm
FSM-300-M-12 Spare Mirror Assy., FSM-300 UV Grade Fused Silica HM.10 Coating, High Power, Nd:YAG, Dielectric, 1064nm
FSM-300-M-13 Spare Mirror Assy., FSM-300 UV Grade Fused Silica HM.30 Coating, High Power, Nd:YAG, Dielectric, 532nm
FSM-300-M-14 Spare Mirror Assy., FSM-300 UV Grade Fused Silica HM.15 Coating, High Power, Nd:YAG, Dielectric, 1064nm
FSM-300-M-15 Spare Mirror Assy., FSM-300 UV Grade Fused Silica HM.35 Coating, High Power, Nd:YAG, Dielectric, 532nm
FSM-300-M-16 Spare Mirror Assy., FSM-300 UV Grade Fused Silica EM.30 Coating, High Power, Eximer, Dielectric, 351-353nm
FSM-300-M-17 Spare Mirror Assy., FSM-300 UV Grade Fused Silica EM.35 Coating, High Power, Eximer, Dielectric, 351-353nm
For additional information on mirror coatings, please see the Mirror Selection Guide: see page 514
Contact Newport if you would like to replace a 2" mirror.
FSM-300
1.42
(36)
2.13
(54)
3.25
(82.6)
3.50
(88.9)
4.09
(103.8)
3.79
(96.2)
TECHNICAL REFERENCE AND
FUNDAMENTAL APPLICATIONS
LENS SELECTION GUIDE SPHERICAL LENSES CYLINDRICAL AND
SPECIALTY LENSES
CLEAR APERTURE
>ø0.80 (20mm)
DIELECTRIC
MIRROR
1.50
(38.1)
.50
(12.7)
.13
(3.2)
.71
(18.1)
2.25
(57.2)
2.13
(54)
2.50
(63.5)
1.12
(28.6)
1.25
(31.7)
1.25
(31.8)
1.04
(26.3)
1.53
(38.7)
.25
(6.4)
5X ø9/32 (7.14mm)
HOLES FOR ø1/4 (M6)
MOUNTING SCREWS
2.63
(66.7)
.66
(16.6)
4X #4-40 SCREWS
ATTACH BASE TO FSM
FSM-300 Series
2.26
(57.3) 15 PIN CONNECTOR
2.24
(56.8)
.38
(9.5)
OPTICS SETS OPTICAL SYSTEMS MIRRORS PRISMS
Email: sales@newport.com • Web: newport.com