THORLABS SA201-EC User manual

SA201(-EC)
Spectrum Analyzer
Controller
Operating Manual

Spectrum Analyzer Controller
Table of Contents
Chapter 1 Warning Symbol Definitions ........................................... 1
Chapter 2 Safety................................................................................. 2
Chapter 3 Overview............................................................................ 3
3.1. Parts List.......................................................................3
3.2. Compatible Fabry-Perot Scanning Heads .......................4
Chapter 4 Description........................................................................ 5
4.1. Detector Gain Adjustment.............................................6
4.2. DC Offset Control ..........................................................6
4.3. Sweep Expansion Control ..............................................6
4.4. Waveform Control ........................................................6
4.5. Power Switch ................................................................6
4.6. Power On Indicator .......................................................6
4.7. Amplitude Control.........................................................7
4.8. Rise Time Control ..........................................................7
4.9. Trigger Output BNC.......................................................8
4.10. Output BNC...................................................................8
4.11. Ground Plug..................................................................9
4.12. AC Input Connector .......................................................9
4.13. PD Amplifier Input BNC .................................................9
4.14. PD Amplifier Output BNC.............................................10
4.15. Voltage Selector Switch...............................................10
Chapter 5 Operation.........................................................................11
5.1. PD Blanking Circuit......................................................11
5.2. Replacing the Fuse ......................................................12
5.2.1. Materials Needed.....................................................................12
5.2.2. Fuse Replacement...................................................................12

Spectrum Analyzer Controller
5.3. Selecting the Line Voltage ...........................................13
5.4. Cleaning .....................................................................13
Chapter 6 Recommended Setup..................................................... 14
6.1. Recommended Setup for SA200 Series Fabry-Perot
Interferometers (Except SA200-30C) ............................14
6.2. Recommended Setup for SA200-30C Fabry-Perot
Interferometer............................................................15
Chapter 7 Specifications ................................................................. 17
7.1. Output Characteristics.................................................17
7.2. Trigger Characteristics ................................................17
7.3. Photodiode Amplifier Characteristics ...........................18
7.4. Physical Features ........................................................19
7.5. Power Supply..............................................................19
Chapter 8 Regulatory.......................................................................20
Chapter 9 Declaration of Conformity .............................................21
Chapter 10 Thorlabs Worldwide Contacts....................................... 22

Spectrum Analyzer Controller Chapter 1: Warning Symbol Definitions
Rev H, November 30, 2021 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

Spectrum Analyzer Controller Chapter 2: Safety
Page 2 6679-D02
Chapter 2 Safety
Precautions of a general nature should be gathered here. Wherever possible,
however, safety warnings, cautions, and notes should only appear immediately
before the instructions to which they apply (versus being listed in this section).
DANGER!
The Thorlabs Spectrum Analyzer Controller, SA201, must be powered off,
unplugged from the AC input source, and disconnected from any piezo
elements prior to replacing the fuse or removal of the cover. Failure to do so
may cause SERIOUS INJURY to the user, since high voltages exist within the
unit.
WARNING!
Complete the setup of the equipment before energizing the laser.
WARNING!
When the laser is energized, always use the proper eye protection relative to the
laser used in the setup. When an invisible laser source is used, use extra
caution during alignment.

Spectrum Analyzer Controller Chapter 3: Overview
Rev H, November 30, 2021 Page 3
Chapter 3 Overview
Thorlabs' Scanning Fabry-Perot (FP) Interferometers are spectrum analyzers that
are ideal for examining fine spectral characteristics of CW lasers. The controller
generates a voltage ramp, which is used to scan the separation between the two
cavity mirrors. The controller provides adjustment of the ramp voltage and scan
time, allowing the user to choose the scan range and speed. An offset control is
provided to allow the spectrum displayed on the oscilloscope to be shifted right or
left. Another convenient feature of the controller is a zoom capability that provides
a 1X, 2X, 5X, 10X, 20X, 50X and 100X increase in the spectral display resolution.
The output TTL level trigger allows the user to externally trigger an oscilloscope
on either the beginning or midpoint of the ramp waveform.
The SA201 also includes a high precision photodetector amplifier circuit used to
monitor the transmission of the cavity. The amplifier provides an adjustable
transimpedance gain of 10,000, 100,000, and 1,000,000 V/A when driving a high
impedance load, such as an oscilloscope. Using the output sync signal from the
controller, an oscilloscope can be used to display the spectrum of the input laser.
The detector circuitry incorporates a blanking circuit, which disables the
photodiode response during the falling edge of the saw tooth waveform.
3.1. Parts List
Below is a list of all components shipped with the SA201 Spectrum Analyzer
Controller.
•SA201 Spectrum Analyzer Controller
•Operating Manual
•120 VAC US Power Supply Line Cord (with the SA201) or 230 VAC
Power Supply Line Cord for Europe (with the SA201-EC)
•125 mA Fuse for use at 230 VAC operation (250 mA fuse installed in unit)

Spectrum Analyzer Controller Chapter 3: Overview
Page 4 6679-D02
3.2. Compatible Fabry-Perot Scanning Heads
This product has been designed to be used with one of our SA200, SA210, or
SA30 Series Scanning Fabry-Perot Interferometers. Below is a list of available
heads. Note this list is subject to change without notice. Please visit the website
for the most current information.
Previous generations of scanning Fabry-Perot interferometers are also compatible
with this product. These items are listed below.
Item #
Description
SA200-2B
290 - 335 nm;
520 - 545 nm
1.5 GHz FSR
SA200-3B
350 - 535 nm,
1.5 GHz FSR
SA200-5B
535 - 820 nm,
1.5 GHz FSR
SA200-8B
820 - 1275 nm,
1.5 GHz FSR
SA200-12B
1275 - 2000 nm,
1.5 GHz FSR
SA200-18C
1800 - 2500 nm,
1.5 GHz FSR
SA200-30C
3000 –4400 nm,
1.5 GHz FSR
Item #
Description
SA210-3B
350 - 535 nm,
10 GHz FSR
SA210-5B
535 - 820 nm,
10 GHz FSR
SA210-8B
820 - 1275 nm,
10 GHz FSR
SA210-12B
1275 - 2000 nm,
10 GHz FSR
SA210-18C
1800 - 2500 nm,
10 GHz FSR
SA30-52
488 –545 nm,
1.5 GHz FSR
Item #
Description
SA200-7A
780 - 930 nm,
1.5 GHz FSR
SA200-9A
900 - 1100 nm,
1.5 GHz FSR
SA200-14A
1450 - 1625 nm,
1.5 GHz FSR
SA200-18B
1800 - 2500 nm,
1.5 GHz FSR
SA200-30B
3000 –4400 nm,
1.5 GHz FSR
Item #
Description
SA210-5A
525 - 650 nm,
10 GHz FSR
SA210-7A
780 - 930 nm,
10 GHz FSR
SA210-9A
900 - 1100 nm,
10 GHz FSR
SA210-12A
1250 - 1400 nm,
10 GHz FSR
SA210-14A
1450 - 1625 nm,
10 GHz FSR
SA210-18B
1800 - 2500 nm,
10 GHz FSR

Spectrum Analyzer Controller Chapter 4: Description
Rev H, November 30, 2021 Page 5
Chapter 4 Description
Figure 1 SA201 Front Panel Controls
Rise Time Control
Power On Indicator
Amplitude Control
Sweep Expansion Control
Detector Gain Adjustment
Waveform Control
DC Offset Control
Output BNC
Trigger Output BNV
Power Switch

Spectrum Analyzer Controller Chapter 4: Description
Page 6 6679-D02
4.1. Detector Gain Adjustment
The SA201 includes a built in photodiode amplifier circuit. This amplifier is
designed specifically to operate with the detector provided with the SA200 series
Fabry-Perot Interferometer, allowing the user to monitor the transmission of the
cavity. While any photodetector may be connected to the amplifier the
specifications, listed in Chapter 3, apply only to detectors supplied with the SA200
series. The amplifier provides a transimpedance gain (current to voltage gain) of
10K, 100K, and 1M V/A while driving a Hi-Z load, such as an oscilloscope. For
better noise and performance characteristics it is recommended that a 50 W coax
cable with a 50 Ω terminating resistor be used. The photodetector input and output
BNC’s are located on the rear panel.
4.2. DC Offset Control
The DC Offset provides a continuously adjustable offset voltage over the range of
0 to 15 V using a 10-turn potentiometer. This offset adds directly to the ramp
signal. The DC offset control is used to adjust the waveform from left to right across
an oscilloscope viewing window, without affecting the calibration of the cavity.
4.3. Sweep Expansion Control
The sweep expansion provides a zoom capability to increase the spectral display
resolution by a factor of 1x, 2x, 5x, 10x, 20x, 50x, and 100x. This is achieved by
scaling the ramp rise time to the sweep expansion.
4.4. Waveform Control
The SA201 allows the user to select between a saw-tooth and triangular waveform.
The saw-tooth waveform is desirable for most applications; however the triangle
waveform is useful for cavity alignment. The SA201 will default to the saw-tooth
waveform during the system power-up. To change the waveform, simply press the
‘WAVEFORM SEL’ button. The selected waveform is indicated by the illuminated
symbol to the right of the waveform select button.
4.5. Power Switch
The power switch is used to toggle the unit on and off.
4.6. Power On Indicator
The power on LED will light when the unit is powered up.