THORLABS S4FC Series User manual

S4FC Series
Fiber-Coupled Laser
Sources
User Guide

S4FC Series Fiber Coupled Laser Source
Table of Contents
Chapter 1Warning Symbol Definitions..............................................................................................1
Chapter 2Safety....................................................................................................................................2
2.1.Laser Safety .....................................................................................................................3
Chapter 3Description...........................................................................................................................4
Chapter 4Setup.....................................................................................................................................5
4.1.Initial Set-up.....................................................................................................................5
Chapter 5Operation..............................................................................................................................6
5.1.Front and Back Panel Overview.....................................................................................6
5.2.Cleaning and Connecting the Fiber Patch Cable .........................................................7
5.3.Powering up the Source .................................................................................................7
5.4.LOCK Button.................................................................................................................... 8
5.5.Adjusting the Laser Temperature .................................................................................. 8
5.6.Adjusting the Laser Output Power ................................................................................8
5.7.Enabling the Laser ..........................................................................................................9
5.8.Turning the Laser Off....................................................................................................10
5.9.Modulating the Laser Output .......................................................................................10
5.10.Computer Controlled Operation ..................................................................................11
5.10.1.GUI Operation .....................................................................................................................11
5.10.2.Command Line Operation ...................................................................................................13
5.11.Keywords (Commands and Queries) ..........................................................................14
Chapter 6Connecting the Safety Interlock.......................................................................................15
Chapter 7General Maintenance.........................................................................................................16
7.1.Cleaning .........................................................................................................................16
7.2.Connector Cleaning ......................................................................................................16
7.3.Fuse Replacement.........................................................................................................17
Chapter 8Troubleshooting.................................................................................................................18
8.1.Error Codes....................................................................................................................18
8.2.Fault Tracing..................................................................................................................19
Chapter 9Specifications.....................................................................................................................20
Chapter 10Mechanical Drawing...........................................................................................................20
Chapter 11Regulatory...........................................................................................................................22
Chapter 12Certificate of Compliance..................................................................................................23
Chapter 13Thorlabs Worldwide Contacts..........................................................................................24

S4FC Series Fiber Coupled Laser Source Chapter 1: Warning Symbol Definitions
October 24, 2017, Rev R Page 1
Chapter 1 Warning Symbol Definitions
Below is a list of warning symbols you may encounter in this manual or on your device.
Symbol Description
Direct Current
Alternating Current
Both Direct and Alternating Current
Earth Ground Terminal
Protective Conductor Terminal
Frame or Chassis Terminal
Equipotentiality
On (Supply)
Off (Supply)
In Position of a Bi-Stable Push Control
Out Position of a Bi-Stable Push Control
Caution: Risk of Electric Shock
Caution: Hot Surface
Caution: Risk of Danger
Warning: Laser Radiation
Caution: Spinning Blades May Cause Harm

S4FC Series Fiber Coupled Laser Source Chapter 2: Safety
Page 2 TTN051387-D02
Chapter 2 Safety
SHOCK WARNING
High voltage inside. To avoid electrical shock, before powering unit, make sure that the protective
conductor of the 3-conductor power cord is correctly connected to the protective earth contact of the
socket outlet. Improper grounding can cause electric shock resulting in severe injury or even death.
Do not operate without cover installed.
WARNING
This unit must not be operated in explosive environments. Do not operate in wet or damp conditions.
Do not obstruct the air-ventilation slots in the housing!
WARNING
Avoid Exposure – Laser Radiation Emitted from apertures.
WARNING
The unit is supplied with either a 115 V parallel blade line cord for North American use or a European
compatible 220 V line cord. For all other applications use an IEC 320 compatible line cord fitted with a
plug appropriate for your particular AC wall socket. Do not replace detachable mains lead with an
inferior cord. This may cause a failure, damage, shock, or injury. Changing of the mains fuse can be
done by the user, refer to section 7.3 on page 17 for proper fuse selection. With the exception of the
mains fuse and the connector (for cleaning), there are no user serviceable parts in this product.
Warning
Mobile telephones, cellular phones or other radio transmitters should not to be used within the range
of three meters of this unit since the electromagnetic field intensity may exceed the maximum allowed
disturbance values according to EN50082-1.
This device can only be returned when packed into the complete original packaging, including all packing inserts.
If necessary, ask for a replacement package.
The maximum USB and BNC cable length is 3 meters in order to avoid a susceptibility to RF interference
according to IEC61000-4-3.
Note: If equipment is used in a manner not specified by the manufacturer, the protection provided by the
equipment may be impaired.
Complies with 21 CFR 1040.10 and 1040.11 except for deviations pursuant to laser notice no. 50, dated 5/27/01.

S4FC Series Fiber Coupled Laser Source Chapter 2: Safety
October 24, 2017, Rev R Page 3
2.1. Laser Safety
The S4FC series of lasers are rated in the 3B Laser Safety Class. According to Laser Institute of America: “A
Class 3B laser is hazardous if the eye is exposed directly, but diffuse reflection such as from paper or other matte
surfaces are not harmful. Continuous lasers in the wavelength range from 315 nm to far infrared are limited to 0.5
W. For pulsed lasers between 400 and 700 nm, the limit is 30 mJ. Other limits apply to other wavelengths and to
ultra-short pulsed lasers. Protective eyewear is typically required where direct viewing of a class 3B laser beam
may occur. Class-3B lasers must be equipped with a key switch and a safety interlock.
According to the revised ANSI Z136.1 Safe Use of Lasers, laser area warning signs should be posted around
Class 3 laser areas and are required to be posted around all Class 3B and 4 laser areas. NOTICE signs are
required for Class 3B and Class 4 lasers during maintenance, servicing, and similar situations.
Additionally, it is necessary to connect the fiber patch cable you will be using to the S4FC fiber output port before
enabling the laser, both for safety reasons and fiber care. Please see section 5.2, page 7 regarding cleaning of
fiber tips in order to prevent fiber damage and system degradation.
LASER RADIATION
AVOID EXPOSURE TO BEAM
CLASS 3B LASER RODUCT
660 nm <65 mW
LASER RADIATION
AVOID EXPOSURE TO BEAM
CLASS 3B LASER RODUCT
637 nm <80 mW
LASER RADIATION
AVOID EXPOSURE TO BEAM
CLASS 3B LASER RODUCT
520 nm <20 mW
LASER RADIATION
AVOID DIRECT EYE EXPOSURE
CLASS 3R LASER PRODUCT
1310 nm <60 mW
LASER RADIATION
AVOID EXPOSURE TO BEAM
CLASS 3B LASER RODUCT
1550 nm <60 mW
LASER RADIATION
AVOID EXPOSURE TO BEAM
CLASS 3B LASER RODUCT
785 nm <110 mW
LASER RADIATION
AVOID DIRECT EYE EXPOSURE
CLASS 3B LASER PRODUCT
808 nm <50 mW
LASER RADIATION
AVOID DIRECT EYE EXPOSURE
CLASS 3B LASER PRODUCT
915 nm <50 mW
LASER RADIATION
AVOID DIRECT EYE EXPOSURE
CLASS 3B LASER PRODUCT
852nm <40 mW
LASER RADIATION
AVOID DIRECT EYE EXPOSURE
CLASS 3B LASER PRODUCT
940 nm <40 mW
LASER RADIATION
AVOID EXPOSURE TO BEAM
CLASS 3B LASER RODUCT
488 nm <25 mW
LASER RADIATION
AVOID EXPOSURE TO BEAM
CLASS 3B LASER RODUCT
473 nm <25 mW
LASER RADIATION
AVOID EXPOSURE TO BEAM
CLASS 3B LASER RODUCT
1064 nm <60 mW
LASER RADIATION
AVOID EXPOSURE TO BEAM
CLASS 3B LASER RODUCT
685 nm <20 mW
LASER RADIATION
AVOID EXPOSURE TO BEAM
CLASS 3B LASER RODUCT
705 nm <20 mW
LASER RADIATION
AVOID EXPOSURE TO BEAM
CLASS 3B LASER RODUCT
642 nm <25 mW
LASER RADIATION
AVOID DIRECT EYE EXPOSURE
CLASS 3B LASER PRODUCT
820 nm <90 mW

S4FC Series Fiber Coupled Laser Source Chapter 3: Description
Page 4 TTN051387-D02
Chapter 3 Description
The Thorlabs S4FC series of Fiber-Coupled Laser Sources provide an independent, high-precision, low-noise,
constant-current source with easy coupling and simple control of laser diode driven fiber optics. The S4FC series
laser sources are available in a number of standard wavelengths with single mode fiber standard.
The S4FC utilizes a microcontroller to fully control the laser’s optical power, temperature, and monitor the system
for fault conditions. The equipped thermo-electric cooler (TEC) stabilizes the Laser output wavelength and is
adjustable from 20 °C to 30 °C.
The front panel includes a 4-digit LED display which indicates the laser power or temperature set-point. Laser
power, which is calculated based on an internal photodiode monitor, and temperature are set by use of rotary
adjustment knobs located on the front panel. Tactile buttons allow for the selection of either laser power or
temperature to be displayed. LED’s indicate the selection of laser power or temperature. The laser output port is
located on the front panel.
The laser controller includes the ability to modulate the output via an external modulation input for analog
modulation. The USB connector on the back panel allows communication with a PC using a GUI or a command
line language (see section 5.9 on page 10). All S4FC series laser sources are equipped with a remote interlock
connector located on the rear panel. In order to enable the laser source, a short circuit must be applied across the
terminals of the remote interlock connector. A shorting pin is included and installed for use without an interlock
circuit.
The S4FC houses a switch mode AC-DC power supply that is compatible and compliant with all international line
voltages.

S4FC Series Fiber Coupled Laser Source Chapter 4: Setup
October 24, 2017, Rev R Page 5
Chapter 4 Setup
4.1. Initial Set-up
The S4FC Laser Source is designed to operate from 85 to 264 VAC and there is no need to make any
adjustments as the switching power supply will determine the correct voltage automatically. Use the proper line
cord for your region.
1. Locate the unit on a dry, level working surface. Verify that the ventilation vents are not obstructed.
2. Make sure the POWER key switch on the front of the unit is in the OFF position (key perpendicular to
working surface).
3. Plug the female end of the AC line cord provided into the AC Input Receptacle on the rear of the unit.
Plug the male end into a properly grounded AC socket.
4. The laser aperture is an FC/PC fiber connector; therefore it is required to use an FC/PC fiber optic patch
cord to connect to the LASER APERTURE on the front panel of the unit. Always clean the ferrule end of
your fiber patch cable prior to inserting it into the output FC Adapter (refer to section 7.2 page 16 for more
information).

S4FC Series Fiber Coupled Laser Source Chapter 5: Operation
Page 6 TTN051387-D02
Chapter 5 Operation
5.1. Front and Back Panel Overview
Figure 1 Front and Rear Panels of Laser Source
Modulation Input
0 to 5 V Max
Remote Interlock Input
Shorting plug supplied and
installed.
USB Input
Fuse Drawer
User replaceable fuse
AC Power IEC
Connector
Laser Output
FC/PC fiber optic
connector
Laser Output Cover
Cover should be replaced
when not in use.
Laser Emission Indicator
Blinks for 5 seconds before
laser turns ON
Power Adjust Knob
4 Digit Display
Laser Enable Button
Press to activate laser
LED Indicators
Bi-color LED’s indicate
selection of mW or temp
and their status
Key Lock Power Switch
Turns power on and off. Key
only removes when off.
Temperature Adjust
Adjust temp set point with
flathead screwdriver.
Lock Button
Locks laser and temp
setpoints to prevent
accidental adjustment
mW/°C Selector Button
Toggles between laser
power and temp control

S4FC Series Fiber Coupled Laser Source Chapter 5: Operation
October 24, 2017, Rev R Page 7
5.2. Cleaning and Connecting the Fiber Patch Cable
Before Enabling the S4FC Laser Source
It is necessary to clean the fiber patch cable connector tip and the connector tip inside the bulkhead connector for
both safety reasons and fiber care. Failure to do so may result in a damaged fiber connector on the user provided
patch cord, the internal fiber connector, or both by burning the fiber end faces if the contaminates are over the
fiber core. See section 7.2 page 16 for instructions on how to clean your connectors.
WARNING
DO NOT connect a fiber patch cord to the laser’s FC/PC bulkhead connector without cleaning the
fiber tips first. DO NOT connect a fiber patch cord to the unit while the laser is enabled. Failure to
follow these precautions may result in permanent damage to the unit.
Make sure your unit is off before inserting the FC/PC fiber connector patch cord into the bulk head connector.
Failure to do so may result in damaging the connector on your user provided patch cord, the internal fiber
connector or both. After the fiber tips are cleaned, carefully align the key on the fiber patch cable connector with
the alignment slot on the S4FC output aperture. Gently insert the fiber and thread the outer sleeve to the output
aperture threads until finger tight.
Make sure the interlock shorting plug or an interlock connector is inserted into the back of the unit. The laser will
not enable if there is no shorting pin or appropriate interlock connection. See the lower image in Figure 1, page 6
for the location of interlock pin.
5.3. Powering up the Source
To turn the unit on, turn the key switch clockwise to the on position. The unit will power up, setting all digits to
flash 8888, then to its default setting. Note that the laser will not be enabled until the ENABLE button is pressed
after the unit has fully powered on.
Notes:
Make sure the interlock input plug is inserted, see Chapter 6 page 15.
An option is available through the GUI or a HyperTerminal command, which will allow the user to save the last
laser power setting upon shutdown. The command is:
START FROM LAST=<0=Off, 1=On>
1 = On: Saves the latest power upon shutdown. During power on, laser power is retrieved. Pressing the
Laser Enable button will display the saved laser power setting, when the 5 second safety delay is up, the
laser is ON at the saved power.
0 = Off: Does not save the power setting of the laser upon shutdown. Upon restart, laser power will be set
to the minimum power.

S4FC Series Fiber Coupled Laser Source Chapter 5: Operation
Page 8 TTN051387-D02
5.4. LOCK Button
The LOCK button can be pressed in the event the user would like to lock the laser and temperature setting to
prevent against accidental adjustment. When LOCK is pressed, the LOCK LED will illuminate. At this time,
adjustment of the rotary knob and adjustment screw will not change the Laser or Temperature set point. Press
LOCK again to un-lock.
Notes:
An option is available through the GUI or a HyperTerminal command, which will allow the user to set the LOCK on
a timeout so that it automatically locks after 3 minutes after the last change. The command is:
AUTO LOCK=<0=Off, 1=On>
1 = On: Sets the LOCK on after 3 minutes of inactivity from last change. The user must press the LOCK
button to release the unit before making a change.
0 = Off: Disables the automatic LOCK on feature.
5.5. Adjusting the Laser Temperature
The laser TEC controller can be adjusted via the small screw in the front panel. The temperature can be adjusted
from 20 °C to 30 °C. Pressing the mW/°C button will display the temperature set point. The LED labeled °C next
to the 4-digit LED display will be green when the temperature is within ±1 °C. The °C LED will turn amber
whenever the temperature moves more than 1 °C from the set point, even if it is in power adjust mode.
Figure 2 View of Front Panel with Temperature Adjust Selected
1. Press the LOCK button so that the LOCK indicator is not lit (unlocked).
2. Press mW/°C button to select °C.
3. Using a small, flat-head screwdriver, turn the adjustment screw clockwise to increase the setpoint and
counterclockwise to decrease the setpoint. The setpoint can be adjusted from 20 °C to 30 °C.
4. While the set point temperature is adjusted, the system will immediately start correcting the laser
temperature.
5.6. Adjusting the Laser Output Power
The optical output power can be adjusted from the front panel using the Power Adjust knob. The power can be
adjusted from 0 to the maximum output power. The mW LED indicator next to the 4-digit LED display will be
green when the power is at the set value. If the power fails to set, the LED will turn amber. Note that the power
displayed is the power at the laser aperture, not at the end of the user’s fiber patch cord. The actual power
at the end of the user’s fiber optic cable may be less than the displayed power depending on the quality of the
connection and pigtail used.