THORLABS SD-OCT Telesto Series User manual

SD-OCT Base Unit
Spectral Domain
OCT System Base Units:
Telesto and Ganymede
Series
User Manual

Original User Manual – not translated

SD-OCT Base Unit
Table of Contents
Chapter 1Introduction.....................................................................................................................1
Safety.......................................................................................................................... 2
Care and Maintenance .............................................................................................. 3
Optical Cleaning..............................................................................................................4 
Fiber Cleaning Using the FBC250 ..................................................................................4
Service ............................................................................................................................4
Accessories and Customization......................................................................................4
Chapter 2Setup................................................................................................................................5
Unpacking .................................................................................................................. 5
System Connections................................................................................................. 5
Base Unit Connections....................................................................................................5
Internal Electrical Connections .......................................................................................6
Electrical Interfaces to Scanner ......................................................................................6
Optical Interface to Scanner..................................................................................... 6
System Installation.................................................................................................... 7
Enable External Trigger ................................................................................................13
Using the Trigger I/O Feature .......................................................................................14
Using the Analog Input Feature ....................................................................................16
Chapter 3Description....................................................................................................................17
Tutorial ..................................................................................................................... 17
Theory ...........................................................................................................................18
Thorlabs SD-OCT System Technology.........................................................................19
Polarization-Sensitive Optical Coherence Tomography ...............................................20
Nomenclature in OCT Imaging......................................................................................21
OCT Base Unit Components .................................................................................. 23
Base Unit.......................................................................................................................23
PC with Graphical User Interface..................................................................................23
SDK ...............................................................................................................................23
Imaging Scanner (Accessory).......................................................................................25
OCT-STAND (Accessory) .............................................................................................27
Chapter 4System Operation.........................................................................................................29
Starting the System................................................................................................. 29
Basic Adjustments .................................................................................................. 29
Adjusting the Focus.......................................................................................................29
Adjusting the Reference Intensity .................................................................................31
Adjusting the Reference Length....................................................................................31
Advanced Adjustments .......................................................................................... 33
Focus and Choice of Objective Lens ............................................................................33
Imaging through Refractive Media ................................................................................34
Optimizing the Sensitivity ..............................................................................................35
Reflecting Surfaces and Interfaces ...............................................................................36
Rough Surfaces ............................................................................................................36
Shutting Down the System..................................................................................... 36
Example Images ...................................................................................................... 37
Chapter 5Imaging Artifacts..........................................................................................................41
Saturation and Non-Linearity ................................................................................. 41
Wrong Reference Intensity Setting........................................................................ 42

SD-OCT Base Unit
Autocorrelation........................................................................................................ 43
Multiple Scattering .................................................................................................. 44
Phase Wrapping and Fringe Washout................................................................... 45
Flipped Image .......................................................................................................... 46
Shadowing ............................................................................................................... 47
Image Distortion by Refractive Media ................................................................... 48
The Group Refraction Index..........................................................................................49
Measurement Depth in OCT Systems ..........................................................................50
Distortions in the Image ................................................................................................51
Chapter 6Sample Applications....................................................................................................53
Synchronous Acquisition of OCT and Fluorescence Using the Analog Input of
Thorlabs Spectral Domain OCT Systems ............................................................. 53
Chapter 7Troubleshooting...........................................................................................................55
Changing the Input Fuses ...................................................................................... 57
Chapter 8Certifications and Compliance...................................................................................58
Declaration of Conformity GAN1x1 Series Base Units........................................ 58
Declaration of Conformity GAN1x1C1 Imaging Systems .................................... 59
Declaration of Conformity GAN3x1 Series Base Units........................................ 60
Declaration of Conformity GAN3x1C1 Imaging Systems .................................... 61
Declaration of Conformity GAN6x1 Series Base Units........................................ 62
Declaration of Conformity GAN6x1C1 Imaging Systems .................................... 63
Declaration of Conformity TEL2x1(PS) Series Base Units.................................. 64
Declaration of Conformity TEL2x1(PS)C1 Imaging Systems .............................. 65
Declaration of Conformity TEL3x1 Series Base Units ......................................... 66
Declaration of Conformity TEL3x1C1 Imaging Systems ..................................... 67
Chapter 9Warranty........................................................................................................................68
Lasers and Imaging Systems................................................................................. 68
Non-Warranty Repairs ............................................................................................ 68
Warranty Exclusions............................................................................................... 68
Chapter 10Specifications...............................................................................................................69
Chapter 11Mechanical Drawings...................................................................................................71
Chapter 12Regulatory.....................................................................................................................72
Waste Treatment is Your Own Responsibility...................................................... 72
Ecological Background .......................................................................................... 72
Chapter 13Thorlabs OCT Support Contact..................................................................................73
Chapter 14Thorlabs Worldwide Contacts....................................................................................74

SD-OCT Base Unit Chapter 1: Introduction
Rev C, June 25, 2021 Page 1
Chapter 1 Introduction
ATTENTION
Please read the instruction manual carefully before operating the OCT base unit. All statements
regarding safety and technical specifications will only apply when the unit is operated correctly.
This equipment is intended for laboratory use only and is not certified for medical applications,
including but not limited to life support situations.
Refer to this manual whenever the following symbols are encountered on the OCT base unit:
Attention symbol indicates that additional information is available in this manual.
Laser Safety symbol indicates that laser radiation is present.
This manual describes the SD-OCT base units of the Telesto and Ganymede Series.
If not otherwise specified, the base units of the Telesto-PS Series are incorporated in the Telesto Series.
ATTENTION
Check the supply voltage of the system before plugging in the computer. Make sure the included
power cords for the base unit, computer, and monitor are connected to a properly grounded
outlet (100 – 240 VAC; 50 – 60 Hz).
Transportation and delivery may cause the OCT base unit to be warm or cool upon receipt.
Please wait for the system to reach room temperature before attempting to operate.
Operate this system on a flat, dry, and stable surface only.
WARRANTY WARNING
Do not open the base unit, imaging scanner or PC. There are no user serviceable parts in this
product. Opening the device will void your warranty. Any modification or servicing of this
system by unqualified personnel renders Thorlabs free of any liability. This device can only be
returned when packed into the complete original packaging, including all foam packing inserts.
If necessary, ask for replacement packaging.
The following symbols are used on the device:
"ON" (power)
"OFF" (power)

Stand-by

Protective earth; protective ground

SD-OCT Base Unit Chapter 1: Introduction
Page 2 MTN020880-D02
Safety
SHOCK WARNING – HIGH VOLTAGE
Before applying power to the system, make sure that the protective conductor of the three-
conductor mains power cord is correctly connected to the protective earth contact of the socket
outlet. Improper grounding can cause electrical shock resulting in severe injury or even death.
Make sure that the line voltage rating agrees with your local supply and that the appropriate
fuses are installed. Fuses should only be changed by qualified service personnel. Contact
Thorlabs for assistance. Do not operate without cover installed. Refer servicing to qualified
personnel.
ATTENTION
Do not obstruct the air-ventilation slots in the computer housing. Do not obstruct air-ventilation
into the bottom of the base unit or out of the exhaust fan on the rear of the unit.
Mobile telephones, cellular phones, or other radio transmitters are 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 IEC 61000-6-1:2005.
The safety of any system incorporating the equipment is the responsibility of the assembler of
the system.
If equipment is used in a manner not specified by the manufacturer, the protection provided by
the equipment may be impaired.
LASER RADIATION WARNING
Laser emission may be emitted
a) from the scan lens of a scanner (intended use)
b) from the back of the base unit when the fiber cap is removed and the fiber disconnected
c) from the output of the fiber when the fiber is not connected to a scanner
Do not look into the optical output when the device is operating. The laser radiation is not visible
to the human eye and can cause serious damage to your eyesight.
The laser class information is also stated on the laser safety labels on the back of the housing.
Example given for class 1M LASER product:
INVISIBLELASERRADIATION

DONOTSTAREINTOBEAMORVIEW
DIRECTLYWITHOPTICALINSTRUMENTS

CLASS1MLASERPRODUCT

CLASSIFIEDACCORDINGTODINEN60825‐1:2014

SD-OCT Base Unit Chapter 1: Introduction
Rev C, June 25, 2021 Page 3
Care and Maintenance
Handle the system with care during transportation and unpacking. Banging or dropping the system can damage
the unit or lower system performance. If the system is mishandled during shipment, the optical components may
become misaligned, which can lead to a decrease in image quality. If this occurs, the system will need to be
realigned by qualified personnel. Please contact Thorlabs’ OCT support (see Chapter 13) for more information.
Do not store or operate in a damp, closed environment.
Do not store or operate on surfaces that are susceptible to vibrations.
Do not expose to direct sunlight.
Do not use solvents on or near the equipment.
Keep away from dust, dirt, and air-borne pollutants (including cigarette smoke). The system is not
designed for outdoor use. Protect the equipment from rain, snow, and humidity.
Do not expose to mechanical and thermal extremes. Protect the equipment from rapid variation in
temperature.
Handle all connectors, both electrical and optical, with care. Do not use unnecessary force, as this may
damage the connectors.
Handle the optical fiber with care. Mechanical stress can decrease performance and potentially destroy
the fiber. Continual bending of the optical fiber can cause damage. It is important, therefore, to keep
the optical fiber patch cable as straight as possible to minimize bending.
Note: The most common cause of low signal intensity is contamination of the fiber due to airborne pollutants.
To minimize exposure, avoid unnecessarily disconnecting the optical fiber patch cable. In addition, it is advisable
to check the fiber before making other adjustments to the optical system, such as changing the focus or optical
path length. Be sure to check the patch cord for loose connections, and make sure that the fiber is kept as
straight as possible.
All lasers, especially lasers with resonator cavities that are defined by mechanical tolerances, are delicate
precision instruments and must be handled accordingly. The OCT base unit is designed to withstand normal
transportation and operating conditions. Do not move the system while it is connected and in operation.

SD-OCT Base Unit Chapter 1: Introduction
Page 4 MTN020880-D02
Optical Cleaning
Good performance and image quality of the OCT imaging system relies on clean optical connections. Whenever
using the Thorlabs OCT system, the following guidelines for optical fiber connection should be followed:
1) Always make sure that the light source is switched off when you clean the fiber.
2) Always inspect and clean the fiber end before plugging it into a receptacle.
3) Always cover the fiber end that is not in use with a fiber cap or dust protection cover.
Use a fiber inspection scope to verify if the fiber cleaning process was successful.
Figure 1 FS201 Extended Mode
Fiber Cleaning Using the FBC250
Fiber bulkheads and connectors can be cleaned using the FBC250 2.5 mm Fiber Bulkhead and Connector
Cleaner. This fiber cleaner features an extended mode, which is useful for panels with multiple bulkhead
connectors or other tight spaces. For detailed cleaning procedures, please see the FBC250 manual on the
Thorlabs website.
Figure 2 FBC250 Fiber Cleaner in Extended Mode
Service
Only trained and approved Thorlabs personnel are qualified to service the system. Please contact Thorlabs’
OCT support (see Chapter 13) for more information.
Accessories and Customization
The OCT base unit can easily be adapted for custom interfaces. To achieve the listed specifications, however,
this system should only be used with accessories provided by Thorlabs. Any modification or maintenance by
unqualified personnel will render the warranty null and void, leaving Thorlabs free of liability. Please contact
Thorlabs’ OCT support (see Chapter 13) for questions on customization.

SD-OCT Base Unit Chapter 2: Setup
Rev C, June 25, 2021 Page 5
Chapter 2 Setup
Unpacking
Carefully unpack the components from the transport boxes. Make sure that all components have been delivered
according to the packing list included in the transport box. After unpacking, store the packing cartons and inserts.
You may need them in case of a service or upgrade of your OCT system.
System Connections
Base Unit Connections
All OCT base unit connections are located on the back of the device.
A. Main Switch
B. Power Socket
C. Interlock Connector (Shipped with Preinstalled Plug)
D. Connection Port for OCTH Imaging Scanner (LEMO, 14 Pin)
E. Connection Port for OCTG and OCTP Galvo-Driven Imaging Scanners (LEMO, 19 Pin)
F. FC/APC Fiber Connection to Imaging Scanner – TEL2x1PS systems feature a preinstalled fiber
instead of this port
G. Auxiliary FC/APC Fiber Connection (FC/APC) – Only in GANx21 series base units
H. Dual Analog IN SMA Connectors and Trigger I/O SMA Connector
I. USB 2.0 B-Type Socket for Connection to PC
J. Trigger SMA Connector
A
B
Figure 3 Top: Possible Connections on the Back of the GAN6x1, TEL2x1(PS), and TEL3x1 OCT Base Units
Bottom: Possible Connections on the Back of the GAN111 and GAN3x1 OCT Base Units
EDC F G H I K
J
L

SD-OCT Base Unit Chapter 2: Setup
Page 6 MTN020880-D02
K. CameraLink Connection
oA0 – Base CameraLink Connector
oA1 – Only Available in TEL3x1 and GAN6x1 Series Base Units
oB0 – Only Available in TEL2x1PS Series Base Units
L. USB 3.0 Connection
oA0 – Base USB 3.0 Connector (Only Available in GAN111 and GAN3x1 Base Units)
Internal Electrical Connections
The USB connection to the PC is used to control communication between the software and the base unit. The
acquisition and synchronization of spectral information is done through the CameraLink and Trigger
connections or the USB 3.0 connection.
Electrical Interfaces to Scanner
For connecting a scanner to the base unit, two different interfaces are available.
The Galvo Scanner connection port is intended for use with the OCTG and OCTP Thorlabs imaging
scanners.
The OCTH Scanner connection port is intended for use with the OCTH Thorlabs imaging scanner.
Furthermore, it allows the use of a custom scanner. It hosts two analog signals for driving separate
actuators (e.g. galvanometer scanners), as well as communication lines and supply voltages.
Electrical Scanner Connection Interfaces
Galvo Scanner Lemo ECG.2B.319.CLL
OCTH Scanner Lemo ECA.1B.314.CLL
Table 1 Electrical Scanner Connection Interface
Please contact Thorlabs’ OCT support (see Chapter 13) for information regarding the pin configuration.
Optical Interface to Scanner
The base unit can incorporate one or two FC/APC fiber interfaces depending on the internal fiber architecture
(see also section 3.1.2):
Base units with an internal circulator support only one port.
Base units using an internal coupler support two FC/APC interfaces. These ports can be used to build
a dual path setup with minimum optical loss. The optical path length difference between the two ports
is not defined.
The Telesto-PS Series base units already come with an attached polarization maintaining fiber; no
additional fiber is required.
Table 2 lists the single mode fiber types used with the different base units (fiber types in customized systems
may differ).
Optical Scanner Connection Interface
Base Unit Series Fiber Connecto
r
Sin
g
le Mode Fibe
r
Ganymede FC/APC Nufern 780
Telesto FC/APC Corning SMF28 Ultra
or Cornin
g
HI-1060
Telesto-PS Permanently Attached to
Base Unit
Corning PANDA PM13-U25A
Key Aligned to Slow Axis
Table 2 Optical Scanner Connection Interface

SD-OCT Base Unit Chapter 2: Setup
Rev C, June 25, 2021 Page 7
System Installation
ATTENTION
Make sure the included power cords for the base unit, computer and monitor are connected to a
properly grounded outlet (100 – 240 VAC; 50 – 60 Hz).
Transportation and delivery may cause the OCT base unit to be warm or cool upon receipt.
Please wait for the system to reach room temperature before attempting to operate.
Operate this system on a flat, dry, and stable surface only.
1) Install the PC, monitor, mouse and keyboard according to the documentation provided by the PC
manufacturer.
2) If applicable, assemble the OCT stand as described in the documents provided in the OCT-STAND
box.
3) If applicable, mount the scanner in the OCT stand by sliding the dovetail at the back of the scanner into
the dovetail slide of the OCT stand.
Figure 4 Mounting the OCTG Scanner into the Dovetail Slide of the OCT Stand
Dovetail
Focus Block
Mounting Adapter

SD-OCT Base Unit Chapter 2: Setup
Page 8 MTN020880-D02
4) For GAN111 and GAN3x1:
Connect the USB 3.0 cable between the A0 Camera connector on the base unit and the PC.
Note: Make sure to use the USB 3.0 cable and to connect the cable to a USB 3.0 port, check for the
blue color to confirm that the cable and port are for USB 3.0.
For TELxx1 and GAN6x1:
Connect the CameraLink and the SMA trigger cables between the CameraLink and Trigger
connectors on the base unit and the PC.
Note: Different types of base units come with different CameraLink configurations (see J in Figure 3.
The markings on the CameraLink cable(s) must match those on the frame grabbers and base unit.
a. For the Telesto-PS Series base units, the trigger cable comes with an SMA connector which
must be connected to the Trigger connector (I in Figure 3), and two Sub-D connectors which
go to the Sub-D sockets on the frame grabber cards in the PC, see Figure 5.
Figure 5 Connection of the SMA-Dual Sub-D cable to both Frame Grabber Cards (Telesto-PS Series Base Units
only)
5) Attach the USB 2.0 cable (I in Figure 3) to the base unit and to the PC.
6) Connect the power supply plug to the socket of the base unit and connect the other end to an electrical
outlet.

SD-OCT Base Unit Chapter 2: Setup
Rev C, June 25, 2021 Page 9
7) Attach the electric connection cable to the imaging scanner. (Note: The electrical and fiber cables of
the OCTH scanner are fixed to the scanner unit)
Align the red dot of the plug to the alignment mark of the electric connection port of the scanner
(shown here: OCTG).
Figure 6 Plugging the Electric Connector into the Scanner
Figure 7 Electric Connector Plugged into the Scanner
Push the connector into the receptacle until you hear a “click” sound, indicating that the connector is locked.
Red Dot
Alignment Mark

SD-OCT Base Unit Chapter 2: Setup
Page 10 MTN020880-D02
8) Connect the fiber to the imaging scanner (not required for OCTH type scanners).
ATTENTION
When installing the fiber, make sure that the fiber tip is not contaminated by dust.
Do not touch the fiber tip!
Remove the dust caps from one fiber end and from the FC/APC fiber connection at the imaging
scanner. Store these with the system packaging.
Inspect the fiber and clean it according to chapter 1.2.2.
Figure 8 Connecting the Fiber to the Imaging Scanner
A) Slide the fiber tip into the center bore of the fiber connection.
B, C) The fiber needs to be oriented in rotation so that the alignment key slides into the mating
part of the scanner’s fiber connector, as shown in Figure 8C.
NOTE: If the key is not properly aligned, you will still be able to secure the fiber, but there
will be significant light losses produced by this incorrect connection.
D) Secure the fiber connection by turning the lock cap clockwise. No force is required for this
operation.
A
DC
B

SD-OCT Base Unit Chapter 2: Setup
Rev C, June 25, 2021 Page 11
9) Attach the electric connection cable to the base unit. Use the Galvo Scanner port for OCTG and
OCTP series scanners or the OCTH Scanner port for OCTH series scanners.
Align the red dot upwards, facing the alignment mark in the base unit.
Figure 9 Installing the Electric Connection Cable at the Base Unit
Push the connector into the receptacle until a “click” sound is heard.
10) Connect the fiber to the base unit. (Not required in Telesto-PS series base units.)
Remove the dust caps from the fiber end and from the FC/APC fiber connector on the base unit.
Inspect the fiber and clean it according to chapter 1.2.2.
ATTENTION
When installing the fiber, make sure that the fiber tip is not contaminated by dust.
Do not touch the fiber tip!
Red Dot
Alignment
Mark

SD-OCT Base Unit Chapter 2: Setup
Page 12 MTN020880-D02
A) Slide the fiber tip into the center bore of the fiber connection.
B), C) The fiber needs to be oriented in rotation, so that the alignment key slides into the mating
part of the probe connector.
D) Secure the fiber connection by turning the lock cap clockwise. No force is needed for this
operation.
A
D
C
B
Figure 10 Connecting the Fiber to the Base Unit

SD-OCT Base Unit Chapter 2: Setup
Rev C, June 25, 2021 Page 13
11) Pull the protective cap off the scan objective.
Do not touch the optical surface of the lens.
Figure 11 Protective Cap
Enable External Trigger
To enable the use of an external A-scan trigger, the trigger cable from the external source must be connected
to the Trigger port with a tee connector. This allows the trigger signal to be inserted into the existing connection,
as shown in Figure 12.
This option is not available in Telesto-PS Series base units.
ATTENTION
To make use of the external trigger, the checkbox to activate the external trigger mode under
"Hardware" in the "Settings" dialog for external A-scan triggering must be active.
If not, the internal trigger will remain active and the scanning process will be disturbed.
Please refer to the ThorImage®OCT Software Manual for more details on how to use the external trigger feature.

SD-OCT Base Unit Chapter 2: Setup
Page 14 MTN020880-D02
Figure 12 External A-Scan Trigger Attached using an SMA Tee Connector
(Analog Inputs and Trigger I/O Connector to the Left)
Using the Trigger I/O Feature
The Trigger I/O feature provides a LVTTL (3.3 V) trigger interface that can be configured as an input or output
(SMA connector Trigger I/O at the backplane of the OCT Base Unit).
An example of this feature is the implementation of a B-scan trigger. Configured as an output, a trigger pulse
will occur after every finished B-scan of the continuous OCT imaging. When using the trigger I/O port configured
as an input, a trigger pulse initiates a single B-scan.
ATTENTION
To ensure correct trigger functionality, use a 50 Ωcoaxial cable and make sure that the
connected device incorporates a 50 Ωinput/output impedance.
If the coaxial cables or the input/output impedance of the connected device differs (e.g. 1 MΩ),
the trigger signal will be distorted and the trigger functionality might not work.
If the input/output impedance of the connected device cannot be adjusted, use an additional
50 Ωfeedthrough terminator in line with the coaxial cable (Thorlabs Part Number T4119).

SD-OCT Base Unit Chapter 2: Setup
Rev C, June 25, 2021 Page 15
Figure 13: SMA Cable Connected to Trigger I/O port

SD-OCT Base Unit Chapter 2: Setup
Page 16 MTN020880-D02
Using the Analog Input Feature
The system is capable of sampling up to two individual analog signals synchronously with the OCT imaging
process (SMA connectors Analog IN1 / Analog IN2 on the back panel of the OCT base unit).
The sampled data can be saved to a file and visualized using the ThorImage®OCT software application. Please
refer to the ThorImage®OCT Software Manual for further information.
The analog input sampling rate is 1 MS/s at 16 Bit. The input range is -10 V to +10 V.
Figure 14: SMA Cable Connected to Analog IN 2