THORLABS SA201 User manual

SA201, SA201-EC
Spectrum Analyzer Controller
Operating Manual

Spectrum Analyzer Controller
Page 1 Rev D, February 26, 2013
Table of Contents
Chapter 1 Overview............................................................................ 3
1.1.1. Parts List......................................................................................3
1.1.2. Compatible Fabry-Perot Scanning Heads ...................................3
Chapter 2 Description........................................................................ 5
Chapter 3 Operation.........................................................................10
3.1. PD Blanking Circuit ...................................................... 10
3.2. Replacing the Fuse....................................................... 11
1.1.3. Cleaning.....................................................................................12
Chapter 4 Recommended Setup..................................................... 13
Chapter 5 Specifications .................................................................14
Chapter 2 Regulatory....................................................................... 17
Chapter 3 Thorlabs Worldwide Contacts....................................... 18

SA201, SA201-EC Chapter 1: Overview
6679-D02 Page 2
Table of Figures
Figure 1: SA201 Front Panel Controls ............................................................... 5
Figure 2: Trigger Logic....................................................................................... 7
Figure 3: Saw tooth Waveform (left), Triangle Waveform (right)........................ 7
Figure 4: SA201 Rear Panel Connections ......................................................... 8
Figure 5: Recommended Setup Diagram ........................................................ 13

Spectrum Analyzer Controller
Page 3 Rev D, February 26, 2013
Chapter 1 Overview
The SA201 is specifically designed to control Thorlabs SA200 Series Fabry Perot
Interferometers. 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 10K, 100K, and 1M 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.
1.1.1. 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)
1.1.2. Compatible Fabry-Perot Scanning Heads
This product has been designed to be used with one of our SA200 or SA210
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.

SA201, SA201-EC Chapter 1: Overview
6679-D02 Page 4
Item # Description
SA200-3B 350-535 nm, 1.5 GHz FSR
SA200-5B 535-820 nm, 1.5 GHz FSR
SA200-7A 780 - 930 nm, 1.5 GHz FSR
SA200-8B 820-1275 nm, 1.5 GHz FSR
SA200-9A 900 - 1100 nm, 1.5 GHz
FSR
SA200-12B 1275-2000 nm, 1.5 GHz
FSR
SA200-14A 1450 - 1625 nm, 1.5 GHz
FSR
SA200-18B 1800-2500 nm, 1.5 GHz
FSR
Item# Description
SA210-3B 350-535 nm, 10 GHz FSR
SA210-5A 525-650 nm, 10 GHz FSR
SA210-5B 535-820 nm, 10 GHz FSR
SA210-7A 780-930 nm, 10 GHz FSR
SA210-8B 820-1275 nm, 10 GHz FSR
SA210-9A 900-1100 nm, 10 GHz FSR
SA210-12A 1250-1400 nm, 10 GHz FSR
SA210-12B 1275-2000 nm, 10 GHz FSR
SA210-14A 1450-1625 nm, 10 GHz FSR
SA210-18B 1800-2500 nm, 10 GHz FSR

Spectrum Analyzer Controller
Page 5 Rev D, February 26, 2013
Chapter 2 Description
Figure 1 SA201 Front Panel Controls
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 Section 1, 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 Ωterminating resistor be used. The Photodetector input and
output BNC’s are located on the rear panel.
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.
Detector Gain
DC Offset Control
Sweep Expansion
Waveform Control
Power Switch
Power On Indicator
Amplitude Control
Rise Time Trigger Output BNC
Output

SA201, SA201-EC Chapter 2: Description
6679-D02 Page 6
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.
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.
Power Switch
The power switch is used to toggle the unit on and off.
Power On Indicator
The power on LED will light when the unit is powered up.
Amplitude Control
The amplitude control allows the user to adjust the ramp amplitude from 1 to 30
V peak to peak using a 10-turn trim pot. Note, the ramp signal is added to the DC
offset. This means that when the offset is set to 0V, the ramp will start a 0V and
increase to the amplitude limit setting. The amplitude is used to determine how
far the mirror will be scanned, or to set the spectral range of the optical head.
Rise Time Control
The rise time control allows the user to continuously adjust the scan rate from
0.01 to 0.1 ms using a 10-turn trim pot. Note the rise time setting may be scaled
by the sweep expansion setting. For example: If the scan rate is set to 0.05 s and
the sweep expansion is adjusted from 1x to 100x then the scan rate will adjust to
5 s. The scaling error is typically less than ±0.5%, providing excellent
measurement capabilities.
Trigger Output BNC
This trigger output signal may be used to externally trigger the oscilloscope. The
trigger is capable of driving 50 Ωterminated cables, as well as Hi Z loads such
as oscilloscopes. The trigger will provide an edge on the beginning and middle of
the scanning ramp. See Figure 2 below.

Spectrum Analyzer Controller
Page 7 Rev D, February 26, 2013
Figure 2 Trigger Logic
Output BNC
The output BNC is used to drive the SA200 scanning piezos from 1 to 45 V. The
output is capable of driving 0.6 µF piezo loads at a ramp rate of 1 ms over the full
voltage range. The output current is internally limited to prevent damage to the
output drive. Note: the output performance specifications assume a Thorlabs
Fabry Perot Interferometer module is connected.
Figure 3 Saw tooth Waveform (left), Triangle Waveform (right)

SA201, SA201-EC Chapter 2: Description
6679-D02 Page 8
Figure 4 SA201 Rear Panel Connections
Ground Plug
This ground plug is for use as a general-purpose ground connection. It is
connected directly to the earth ground connection of the input power plug.
AC Input Connector
This is the line voltage input connection. IMPORTANT: The unit is configured for
100/115 VAC, 50 – 60 Hz from the factory. To operate at 230 VAC see page 11.
PD Amplifier Input BNC
This input BNC is used to interface the photodetector, provided with the SA200
scanning heads, to the amplifier circuit. The photodiode amplifier is configured to
operate with the Thorlabs supplied photo detectors; however it is possible to
operate user supplied photo detectors. To do so, the BNC center contact must be
connected to the photo detector cathode and the BNC shell must be connected
to the photodiode anode (unbiased operation). If a biased detector is to be used
the BNC shell must be connected to the bias ground and the bias voltage must
be negative for the circuit to operate properly.
PD Amplifier Output BNC
This BNC is the amplifier output and may be connected directly to an
oscilloscope to view the cavity spectrum. The amplifier gain will be set using the
front panel ‘DETECTOR’ control knob. The amplifier output includes a 50 Ω
series resistor to minimize noise when operating with a 50 Ωcoax cable. For best
Ground Plug
A
C Input Connecto
r
PD Amplifier Input BNC
PD Amplifier Output BNC
Voltage Selector

Spectrum Analyzer Controller
Page 9 Rev D, February 26, 2013
results, a 50 Ωload resistor is recommended at the oscilloscope. Note, the
amplifier gain will be halved with a 50 Ωload connected.
Voltage Selector Switch
The voltage selector switch allows the user to select the input line voltage. The
factory default setting is 100/115 VAC as shown in figure 4. To operate at 230
VAC, this switch will have to be moved to the 230 V position. The line fuse will
also need to be changed to properly protect the unit. See page 11 for detailed
instructions.

SA201, SA201-EC Chapter 3: Operation
6679-D02 Page 10
Chapter 3 Operation
3.1. PD Blanking Circuit
The detector amplifier includes a blanking circuit, which blocks any photodetector
response during the falling edge of the saw tooth waveform. This is very useful
when triggering on the photodiode spectral response, because unwanted signals
while the cavity resets will be removed. The blanking is not available when using
the triangle waveform, since it is useful to see the rising and falling response
overlapped during system alignment. This feature may be disabled as described
below:
IMPORTANT
Disconnect the scanning head or any piezo device from the SA201 output.
Disconnect the power cord.
Do not open the unit if the power cord is connected.
1 Remove the two screws securing the enclosure cover with a Phillips head
screwdriver. The screws are located on the bottom side, rear corners of the
unit. Do not lose the screws.
2 Carefully remove the cover by sliding toward the rear of the unit.
3 Locate the JP3 header. It is positioned in front of the heat sink and will have
a shorting jumper on pin 1.
4 Remove the shorting jumper and place across (shorting) the JP3 pins to
disable the blanking circuit. The default setting will be blanking enabled. The
jumper will not be shorting the pins.
5 Replace the enclosure cover and secure with the enclosure screws.
Jumper 3
Blue shorting
cap over pin 1
!
!

Spectrum Analyzer Controller
Page 11 Rev D, February 26, 2013
3.2. Replacing the Fuse
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.
Materials Needed
•SA201 Operating Manual – The most recent version of this operating
manual will be available on the Thorlabs web site.
•250 mA Type ‘T’ Slow Blow Fuse – The 250 mA fuse is installed from
the factory. This must be installed when operating the unit at 100/115
VAC.
•125 mA Type ’T’ Slow Blow Fuse – The 125 mA fuse is required for 230
V operation only. Thorlabs supplies a 125 mA fuse with all of its SA201
units and must be installed when operating at 230 VAC.
•Phillips Head Screwdriver (#2 Preferred) – We do not recommend using
electrically powered screwdrivers.
Fuse Replacement
IMPORTANT
Disconnect the scanning head or any piezo device from the SA201 output.
Disconnect the power cord.
Do not open the unit if the power cord is connected.
1 Remove the two screws securing the enclosure cover with a Phillips
head screwdriver. The screws are located on the bottom side, rear
corners of the unit. Do not lose the screws.
2 Carefully remove the cover by sliding toward the rear of the unit.
!
!
!
!

SA201, SA201-EC Chapter 3: Operation
6679-D02 Page 12
3 Locate the fuse box between the input line voltage connector and the
transformer.
4 Remove the fuse cover and slide the old fuse out.
5 Install the new fuse into the fuse cover and place back into the fuse box.
(250 mA for 100/115 VAC and 125 mA for 230 VAC)
6 Replace the enclosure cover and secure with the enclosure screws.
Selecting the Line Voltage
1. Replace the line fuse as described above.
2. Locate the voltage selector switch on the rear panel. See page 9.
3. Switch to the appropriate line voltage.
4. Install the appropriate line cord.
1.1.3. Cleaning
The SA201 should only be cleaned with a soft cloth and a mild soap detergent or
isopropyl alcohol. Do not use a solvent-based cleaner.
Fuse with
Fuse Cover on

Spectrum Analyzer Controller
Page 13 Rev D, February 26, 2013
Chapter 4 Recommended Setup
Figure 5 Recommended Setup Diagram
PD AMPLIFIER
OUTPUT
INPUT
TRIGGERCHANNEL 2CHANNEL 1
OUTPUT
TRIGGER
115 V
VOLTAGE
SELECT
SA201 REAR PANEL
OSCILLOSCOPE
SA201 FRONT PANEL
DETECTOR
POWER
SCAN CONTROLS
SPECTRUM ANALYZER CONTROLER
SELECT
CALIBRATION
AMPLITUDE RISETIME
GAIN
SA200-xB
FSR=x.xGhz

SA201, SA201-EC Chapter 5: Specifications
6679-D02 Page 14
Chapter 5 Specifications
Output Characteristics
Item # SA201
Waveforms Saw tooth / Triangle
Default Waveform Saw tooth
Saw tooth Fall Time 1 ms Typical
Output Voltage Range 1 to 45 V (offset + amplitude)
Max Supply Current a15 mA
Short Circuit Current b26 mA Max
Short Circuit Duration bContinuous
Offset Adj. Range 0 to 15 VDC
Amplitude Adj. Range 1 to 30 V
Rise Time Adj. Range c
0.01 to 0.1 s @ 1X Sweep
Exp.
1 to 10 s @ 100X Sweep
Exp.
Sweep Expansion Settings 1X, 2X, 5X, 10X, 20X, 50X,
100X
Sweep Scale Error d±0.5%
Output Noise e1 mVRMS (~6.6 mVPP)
Trigger Characteristics
Item # SA201
Trigger Output Voltage TTL levels
VOH (RL = 50 W) 2 V Min
VOL (RL = 50 W) 0.5 V Max
Trigger Load Impedance 50 W/Hi-Z
Trigger Rising Edge
f
Ramp Start
Trigger Falling Edge
f
Ramp Midpoint

Spectrum Analyzer Controller
Page 15 Rev D, February 26, 2013
Photodiode Amplifier Characteristics
Item # SA201
Gain Steps 0, 10, 20 dB
Transimpedance Gain (Hi-Z) 10K, 100K, 1M V/A
Transimpedance Gain (50Ω)
7
5K, 50K, 500K V/A
Gain ErrorG±0.1% @ 10K (±0.12%)
±0.12% @ 100K (±0.15%)
±0.14% @ 1M (±0.3%)
Output Impedance 50 Ω
Load Impedance 50 Ω/Hi-Z
Output Voltage (Hi-Z load) 0 – 10 V Min
Output Voltage (50Ωload) 0 – 5 V Min
Max Output Current h100 mA
Bandwidth h250KHz
Noise (RMS) h<0.1 mV @ 10K
0.2 mV @ 100K
1.5 mV @ 1M
Offset h±1 mV @ 10K
±5 mV @ 100K
±20 mV @ 1M
Physical Features
Item # SA201
Dimensions (W x H x D) 5.8" x 2.8" x 12.5" (147 mm x 71 mm x
317.5 mm)
Input and Output
Connectors
BNCs
Offset Control 10-turn Potentiometer
Amplitude Control 10-turn Trim pot
Rise Time Control 10-turn Trim pot
Sweep Expansion Control 7-Position Rotary Switch
Photodiode Gain Control 3-Position Rotary Switch
Waveform Select Pushbutton w/ Illuminated Indicators
PD Amplifier Features Blanking with Saw Tooth Waveform
Falling Edge
Operating Temperature 10 to 40 ºC
Storage Temperature 0 to 85 ºC

SA201, SA201-EC Chapter 5: Specifications
6679-D02 Page 16
Power Supply
Item # SA201
Supply Type Linear
Voltage Selection Switch Selectable Between 115/230 VAC
Input Voltage 100/115/230 VAC
Line Frequency 50 – 60 Hz
Input Power 15 W Max
Fuse Ratings 250 mA @ 100/115 VAC, 125 mA @ 230
VAC
Fuse Type Slow Blow Type ‘T’
a) Achieved during the saw tooth waveform fall time. This is calculated by
(ma)=(μF)(∆
)
∆
b) The output drive amplifier will current limit the load to 26 mA max. Although
the unit may operate continuously under these conditions, it is not
recommended since the unit will heat up causing stress to the electronics.
c) The rise time adjustment range for each sweep setting is as follows:
=(0.01 × SweepExpansionSetting)to(0.1 × SweepExpansionSetting)
d) Defined as the scaling error between 1X and any other gain settings (ex. 2X
± 0.5%).
e) Measures with SA200 series scanning head connected to output.
f) ‘Ramp’ refers to the rising, or scanning, edge of the ‘Output’ waveform.
g) The gain error does not apply when using a 50 Ωload since the user-
installed output terminator will probably have a resistance tolerance greater
than the gain errors above. Also note that the 50 W output series resistance
is 49.9 W ± 1%. This will also factor into gain error when using a 50 Ωload.
h) Test performed with a 50 Ωterminator and a 6’ (~1.8 m) 50 Ωcoax cable.

Spectrum Analyzer Controller
Page 17 Rev D, February 26, 2013
Chapter 2 Regulatory
As required by the WEEE (Waste Electrical and Electronic Equipment Directive)
of the European Community and the corresponding national laws, Thorlabs offers
all end users in the EC the possibility to return “end of life” units without incurring
disposal charges.
•This offer is valid for Thorlabs electrical and electronic equipment:
•Sold after August 13, 2005
•Marked correspondingly with the crossed out
“wheelie bin” logo (see right)
•Sold to a company or institute within the EC
•Currently owned by a company or institute
within the EC
•Still complete, not disassembled and not
contaminated
As the WEEE directive applies to self contained
operational electrical and electronic products, this end of
life take back service does not refer to other Thorlabs products, such as:
•Pure OEM products, that means assemblies to be built into a unit by the
user (e.g. OEM laser driver cards)
•Components
•Mechanics and optics
•Left over parts of units disassembled by the user (PCB’s, housings etc.).
If you wish to return a Thorlabs unit for waste recovery, please contact Thorlabs
or your nearest dealer for further information.
2.1. Waste Treatment is Your Own Responsibility
If you do not return an “end of life” unit to Thorlabs, you must hand it to a
company specialized in waste recovery. Do not dispose of the unit in a litter bin
or at a public waste disposal site.
2.2. Ecological Background
It is well known that WEEE pollutes the environment by releasing toxic products
during decomposition. The aim of the European RoHS directive is to reduce the
content of toxic substances in electronic products in the future.
The intent of the WEEE directive is to enforce the recycling of WEEE. A
controlled recycling of end of life products will thereby avoid negative impacts on
the environment.
Wheelie Bin Logo

SA201, SA201-EC Chapter 3: Thorlabs Worldwide Contacts
6679-D02 Page 18
Chapter 3 Thorlabs Worldwide Contacts
USA, Canada, and South America
Thorlabs, Inc.
56 Sparta Avenue
Newton, NJ 07860
USA
Tel: [phone]
Fax: [phone]
www.thorlabs.com
www.thorlabs.us (West Coast)
Email: [email protected]
Support: [email protected]
UK and Ireland
Thorlabs Ltd.
1 Saint Thomas Place, Ely
Cambridgeshire CB7 4EX
Great Britain
Tel: [phone]
Fax: [phone]
www.thorlabs.com
Email: [email protected]
Support: [email protected]
Europe
Thorlabs GmbH
Hans-Böckler-Str. 6
85221 Dachau
Germany
Tel: [phone]
Fax: [phone]
www.thorlabs.de
Email: [email protected]
Scandinavia
Thorlabs Sweden AB
Mölndalsvägen 3
412 63 Göteborg
Sweden
Tel: [phone]
Fax: [phone]
www.thorlabs.com
Email: [e-mail]
France
Thorlabs SAS
109, rue des Côtes
78600 Maisons-Laffitte
France
Tel: [phone]
Fax: [phone]
www.thorlabs.com
Email: [email protected]
Brazil
Thorlabs Vendas de Fotônicos Ltda.
Rua Riachuelo, 171
São Carlos, SP 13560-110
Brazil
Tel: [phone]
Fax: [phone]
www.thorlabs.com
Email: [e-mail]
Japan
Thorlabs Japan, Inc.
Higashi-Ikebukuro Q Building 1F
2-23-2, Higashi-Ikebukuro,
Toshima-ku, Tokyo 170-0013
Japan
Tel: [phone]
Fax: [phone]
www.thorlabs.jp
Email: [email protected]
China
Thorlabs China
Room A101, No. 100
Lane 2891, South Qilianshan Road
Putuo District
Shanghai
China
Tel: [phone]
Fax: [phone]
www.thorlabschina.cn
Email: [email protected]om

www.thorlabs.com