THORLABS OTKB/M User manual

Modular Tweezers
OTKB(/M)
User Guide

Modular Optical Tweezers
Table of Contents
Chapter 1Warning Symbol Definitions..............................................................................................1
Chapter 2Safety....................................................................................................................................2
Chapter 3Shipping List........................................................................................................................3
3.1.OTKB-1: Laser Segment .................................................................................................3
3.2.OTKB-2: Beam Expander Segment ...............................................................................3
3.3.OTKB-3: Vertical Segment..............................................................................................3
3.4.OTKB-4: Stage Segment.................................................................................................3
3.5.OTKB-5: Camera Segment .............................................................................................4
3.6.OTKB Accessories, Objective, Condenser ...................................................................4
Chapter 4Introduction..........................................................................................................................5
Chapter 5System Setup.......................................................................................................................6
Chapter 6Setup Details.......................................................................................................................13
Chapter 7Sample Preparation and Measurement...........................................................................14
Chapter 8Accessories and Add-on Modules...................................................................................15
Chapter 9Key Features and Specifications.....................................................................................16
9.1.Features .........................................................................................................................16
9.2.Specifications ................................................................................................................16
Chapter 10Regulatory...........................................................................................................................17
Chapter 11Thorlabs Worldwide Contacts..........................................................................................18

Modular Optical Tweezers Chapter 1: Warning Symbol Definitions
Rev N, August 17, 2018 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

Modular Optical Tweezers Chapter 2: Safety
Page 2 19590-D02
Chapter 2 Safety
All statements regarding safety of operation and technical data in this instruction manual will only apply when the
unit is operated correctly.
WARNING
Changing the laser diode drive current limit or the TEC drive current on the laser control unit can
result in permanent damage to the laser if the limit values of the laser are exceeded.
WARNING
The modular optical tweezers system enables the user to access the laser beam without using
tools, e.g. by removing the filter cube from the system. Use proper laser safety precaution at all
times and check with your local laser safety officer regarding necessary precautions.
CAUTION
The included laser diode is sold as a component. The purchaser assumes the responsibility to
comply with US 21 CFR 1040.10, US 21 CFR 1040.11, and IEC 60825-1, Edition 1.2
CAUTION
Latex gloves should be worn to prevent oil from fingers from reaching all optical surfaces.
Make sure you use appropriate laser safety glasses during operation.
WARNING
Avoid Exposure – ASE and laser radiation emitted from apertures.
Never look directly into beam
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Modular Optical Tweezers Chapter 3: Shipping List
Rev N, August 17, 2018 Page 3
Chapter 3 Shipping List
The modular tweezers system OTKB(/M) is shipped partially preassembled. The list below describes the parts /
segments included. Each segment is bagged separately. Segment 2 and 4 are completely assembled, the other
segments include individual pieces as listed below.
3.1. OTKB-1: Laser Segment
Item # Description Quantity
BL976-SAG300 Butterfly Laser Diode (Trapping Laser) 1
P3-980A-FC-1 Single Mode Patch Cable, FC/APC, 1 m Long 1
CLD1015 Laser Diode Driver with Mount and Preinstalled ADAFC4 1
TC06APC-980 FC/APC Triplet Collimator, f=6.11 mm, 980 nm, NA=0.28 1
ER6 6" Cage Rods Used During Alignment 2
VRC4CPT Cage System Alignment Plate with IR Disk 1
VRC5 IR Viewing Card 1
AD12F Fiber Collimation Adapter 1
3.2. OTKB-2: Beam Expander Segment
Item # Description Quantity
- Optomechanical Assembly with Mounted Optics 1
CL6 Mounting Clamps 6
3.3. OTKB-3: Vertical Segment
Item # Description Quantity
- Optomechanical Assembly with Mounted Optics 1
CL5 Large Mounting Clamps 2
TPS101 5 Volt Power Supply for Light Source 1
3.4. OTKB-4: Stage Segment
Item # Description Quantity
MAX311D
(MAX311D/M) 3-Axis Piezo Stage with Feedback and Differential Drives 1
KPZ101 Kinesis Piezo Motor Controller 3
KCH601 6 Port Kinesis Cube Hub 1
MAX3SLH Sample Slide Holder 1
P2 (P50/M) Ø1.5" Mounting Post x 2" (50 mm) 4
PB2 (PB2/M) Mounting Post Base 4
PS3 (PS15/M) 1/2" Mounting Post Shim 4
TBB0606
(TBB1515/M) Large Area Translation Stage 1
CL5 Large Mounting Clamps 4
AP90 Right Angle Mounting Plate for K-Cube Hub 1
- M3 screws, 10 mm Long to Mount Sample Holder 4
- 2 mm L-Key 1

Modular Optical Tweezers Chapter 3: Shipping List
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3.5. OTKB-5: Camera Segment
Item # Description Quantity
- Optomechanical Assembly with Mounted Optics and Camera 1
3.6. OTKB Accessories, Objective, Condenser
Item # Description Quantity
SH25S038
(SH6MS10)
1/4"-20, 3/8" SS Socket Head Cap Screw
(M6, 10 mm SS Socket Head Cap Screw) 10
SH6MS12
(SH6MS12)
1/4"-20, 5/8" SS Socket Head Cap Screw
(M6, 12 mm SS Socket Head Cap Screw) 10
SH25S125
(SH6MS25)
1/4"-20, 1-1/4" SS Socket Head Cap Screw
(M6, 25 mm SS Socket Head Cap Screw) 10
W25S050 M6 Washer 30
OTKCON Nikon 10X Condenser 1
OTKOBJ Nikon 100X, 1.25 NA Objective 1

Modular Optical Tweezers Chapter 4: Introduction
Rev N, August 17, 2018 Page 5
Chapter 4 Introduction
In 2007, three researchers in the Department of Biological Engineering at MIT – Steve Wasserman, David
Appleyard, and Matthew Lang – built an optical trapping setup for use in teaching labs. Their results were published
in the American Journal of Physics [S. Wasserman, D. Appleyard, and M. Lang, Optical Trapping for
Undergraduates, Am. J. Phys. 75, (2007)]. Based on their design, Thorlabs has collaborated with the
aforementioned authors to design a modular tweezers system that includes all necessary components and provides
the same capabilities. Moreover, since Thorlabs’ components are designed to be compatible with each other, the
OTKB modular tweezers system is easily modified to provide additional functionalities as your research needs
evolve. For example, an excitation light source can be added by incorporating a beam splitting cube into the beam
path allowing e.g. fluorescence measurements. The simple and modular nature of the system allows you to adapt
it for a wide variety of applications. Additional modules can be added any time, such as the OTKB-FL fluorescence
module.

Modular Optical Tweezers Chapter 5: System Setup
Page 6 19590-D02
Chapter 5 System Setup
Throughout the setup various hex keys are required to mount components. To remove or clamp cage system
components generally a 0.05" or 1.3 mm hex key can be used. During the alignment of the vertical segment the
upper dichroic needs to be removed (see step 4). For this a 1/16" or 1.5 mm hex key can be used.
Step 1: Laser Segment (OTKB-1)
Even though the description below will give a quick summary on how to use the laser diode driver (CLD1015), we
highly recommend that the user reads the laser control manual.
CAUTION
Laser diode is highly sensitive to electromagnetic discharge. Make sure to wear ESD protection at
all times when handling the diode.
Remove the lid from the laser diode controller and mount the laser diode as shown in Figure 1. Make sure the laser
diode orientation corresponds to a type 1 pump diode. Use the mounting screws provided with the controller to
attach the diode to the controller mount. This will ensure a good thermal contact between laser and mount.
We recommend coiling the fiber so that it can be placed inside the controller. Do not bend the fiber too tightly, this
might break the fiber. Make sure to clean the fiber before connecting. Plug the FC/APC fiber connector into the feed
through receptacle on the rear side of the controller. Note that the receptacle may be on the opposite side from the
picture below. Make sure that you rotate the fiber connector until the key on the connector snaps into the groove
on the receptacle. Then use the locking mechanism to screw the connector onto the receptacle.
Connect the patch cable (P3-980A-FC-1) on the outside of the back of the controller. The other end of the patch
cable plugs into the collimator on the beam expander segment (see step 2).
Figure 1 Left Side: Laser controller with diode installed. Right side: Collimator with adapter.
Take the laser collimator (Thorlabs part TC06PAC-980) and connect it to the adapter (Thorlabs part AD12F) as
shown in Figure 1 (right side).
The laser controller (Thorlabs part CLD1015) requires settings as shown in Figure 2 and Figure 3.
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Modular Optical Tweezers Chapter 5: System Setup
Rev N, August 17, 2018 Page 7
Figure 2 Laser controller screen at start-up and when entering ‘Menu’.
Figure 3 Laser Controller Screens
Laser Driver Setup: set 600 mA as Laser Current Limit,
enable Noise Reduction Filter
Laser Protection Menu: Use the default settings
Photodiode Input Menu: The Laser is being used in constant
current mode. Input Current Range = 20 mA, BIAS voltage
level = 0.1 V, Photodiode response = 1000 mA/W
TEC Driver Menu: The TEC Current limit should be set to
1.5 A.
PID Control Loop Menu: Adjust Integral Gain (~0.1 As/K
increments) until the Temperature Deviation is minimized,
ideally it should show 0.00 °C
Thermistor Calibration Menu: Use default settings for the
Thermistor Calibration.

Modular Optical Tweezers Chapter 5: System Setup
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Step 2: Beam Expander Segment (OTKB-2)
Mount the beam expander segment onto your optical table or breadboard. Six small clamps (Thorlabs item number
CL6) will be used to clamp the segment down onto the table. Only tighten the screws at the laser port for now.
Remove the caps which were used as protection during shipment. Connect the laser collimator/adapter built in step
1 to the laser port. Connect the patch cord coming from the laser controller.
Figure 4 Left: Beam expander segment. Right: Collimator and patch cord connected to beam expander
segment.
Open the beam expander segment by loosening the two set screws on the cage plate mirror 1, see Figure 4.
Remove the lens tube assembly so that the beam is accessible after Mirror 1. Temporarily move the cage rod
connected to the top of the laser safety cylinder, so that you can put the cage alignment plate (Thorlabs item number
VRC4CPT) in place which is included in the laser segment as shown in Figure 5. Turn the laser on and use the
adjusters on the right angle mirror mount to center the beam. The laser current can be set to around 100 mA for
these alignment steps. Follow all laser safety regulations.
Figure 5 Beam expander segment opened to align first mirror.
Trap Port
Mirror 1
Mirror 2
Camera
Port
Lase
r
Port