THORLABS vytran LDC450B User manual

LDC450B
Large Diameter Fiber
Cleaver
User Guide

LDC450B
Table of Contents
Chapter 1 Warning Symbol Definitions.............................................................................................. 1
Chapter 2 Safety .................................................................................................................................... 2
Chapter 3 Description........................................................................................................................... 3
3.1. Introduction .....................................................................................................................3
3.2. Parts Checklist ................................................................................................................3
3.3. Shipping Fixture..............................................................................................................4
3.4. Accessories.....................................................................................................................5
3.5. Control Overview.............................................................................................................6
3.6. Indicator lights.................................................................................................................6
Chapter 4 Setup ..................................................................................................................................... 8
4.1. Initial Setup......................................................................................................................8
4.2. Power-up..........................................................................................................................9
4.3. Performing the First Cleave .........................................................................................10
4.4. Shut-down......................................................................................................................10
Chapter 5 Theory of Cleaving.............................................................................................................11
5.1. Specialty Fiber Cleaving Processes............................................................................11
Chapter 6 Cleaving...............................................................................................................................12
6.1. Overview ........................................................................................................................12
6.2. The Cleave Process ......................................................................................................12
6.3. The Fiber Holding Blocks, Inserts, Lifting Levers, and Thumbscrews....................14
6.4. Stripping the Fiber ........................................................................................................16
6.5. Loading the Fiber..........................................................................................................16
6.6. Cleaving the Fiber.........................................................................................................18
6.7. Unloading the Fiber.......................................................................................................19
6.8. Changing the Fiber Holding Block Inserts..................................................................20
6.9. Specialty Cleave Process.............................................................................................22
Chapter 7 Using the Handset to Control the LDC450B...................................................................24
7.1. Power Up........................................................................................................................24
7.2. Cleave.............................................................................................................................24
7.3. Edit..................................................................................................................................25
7.4. File..................................................................................................................................28
7.5. Tools...............................................................................................................................30
Chapter 8 Maintenance........................................................................................................................37

LDC450B
8.1. Inspecting the Fiber Holding Blocks...........................................................................37
8.2. Inspecting the Cleave Blade.........................................................................................38
8.3. Re-Positioning the Cleave Blade .................................................................................39
8.4. Replacing the Cleave Blade .........................................................................................40
8.5. Load Cell Calibration ....................................................................................................42
8.6. Battery replacement......................................................................................................42
Chapter 9 Accessories.........................................................................................................................44
9.1. Fiber Holder Inserts ......................................................................................................44
Chapter 10 Specifications .....................................................................................................................48
Chapter 11 Servicing and Troubleshooting........................................................................................49
11.1. Packaging ......................................................................................................................49
11.2. Frequently Asked Questions........................................................................................50
Chapter 12 Regulatory...........................................................................................................................51
Chapter 13 CE Certificate......................................................................................................................52
Chapter 14 Thorlabs Worldwide Contacts..........................................................................................53

LDC450B Large Diameter Cleaver Chapter 1: Warning Symbol Definitions
Rev A, July 28, 2020 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

LDC450B Large Diameter Cleaver Chapter 2: Safety
Page 2 TTN197399-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
Use great care when working near or handling the cleave blade, as the diamond tip is extremely sharp
and can very easily cut through skin.
WARNING
Do not put your fingers between the left fiber holding block and the cleave mechanism when the left
fiber holding block is moving inwards, as they may be pinched.
CAUTION
Damage to the diamond blade may occur if an attempt is made to cleave a coated section of fiber;
make sure that the fiber is stripped down to bare glass and is cleaned thoroughly at the point where
the blade will contact the fiber.
CAUTION
The Cleave Blade should never touch the fiber on the initial, fast move towards the fiber,
or damage to the blade could result.
CAUTION
Do not change the top insert without a bottom insert in place, the top insert can get stuck in the lower
channel.

LDC450B Large Diameter Cleaver Chapter 3: Description
Rev A, July 28, 2020 Page 3
Chapter 3 Description
3.1. Introduction
The LDC450B Large Diameter Fiber Cleaver is designed for cleaving optical fibers with claddings from Ø200 μm to
Ø800 μm with a high degree of accuracy. Intended to be a portable device, this unit provides ease of use and
versatility in manufacturing or research environments. The LDC450B fiber cleaver produces flat cleaves
perpendicular to the length of the fiber.
This fiber cleaver employs a tension-and-scribe cleave method, whereby axial tension is first applied to the fiber
followed by an automated scribe process utilizing a diamond cleave blade. After the blade scribes the fiber, tension
is maintained, causing the scribe to propagate through the fiber and complete the cleave. This method produces
consistent low-angle cleaves with mirror-quality end-face finishes, which are ideal for splicing, and has a cleave
angle accuracy of ±0.5°.
The LDC450B fiber cleaver accepts transfer inserts used in the GPX series of fiber splicers and glass processors,
which makes accurate registration of the fiber position between devices simple to achieve.
3.2. Parts Checklist
Check to make sure that you have the following items:
•The LDC450B Fiber Cleaver
•Shipping Fixture (on unit –see Section 3.3)
•12V DC Power Supply
•Region-Specific Power Cord
•Handset Controller
•Wye Cable
•This Operator’s Manual
•3/32” Hex Key
•0.050” Hex Key
•0.035” Hex Key
•Tweezers
•Nylon Brush
•Canvas Bag
•Bottom Inserts (Purchased Separately)
•Top Inserts (Purchased Separately)

LDC450B Large Diameter Cleaver Chapter 3: Description
Page 4 TTN197399-D02
Figure 1 The LDC450B and Accessories
If you ordered additional inserts, then they should be in the box as well.
If you are missing any of the accessories or need replacements, please contact the distributor from whom you
bought the cleaver. Visit https://www.thorlabs.com/locations.com for contact information.
NOTE: Please save the packaging material for returning the unit back to Thorlabs for service. This packaging will
reduce the risk of damage during shipment.
Figure 2 Packaging Material Should be Saved
3.3. Shipping Fixture
The left fiber holding block of the LDC450B fiber cleaver can be moved out of alignmnent if the unit is jarred violently.
In order to stop this from happening during shipping, each unit is provided with a shipping fixture which is used to

LDC450B Large Diameter Cleaver Chapter 3: Description
Rev A, July 28, 2020 Page 5
lock the left fiber holding block in place with respect to the rest of the unit. After unpacking the unit, loosen the set
screws in the back of the lids using the 0.035” hex key and slide out the shipping fixture.
Figure 3 Removing the Shipping Fixture
Be sure to save the shipping fixture so that you will be able to use it in the event that you have to return the unit for
service.
Figure 4 Shipping Fixture
3.4. Accessories
It is necessary to purchase one bottom insert and one top insert to hold the coated fiber in the left fiber holding
block, and one bottom insert and one top insert to hold the bare fiber in the right fiber holding block. The inserts
should be selected based on the diameter of the fiber that is to be cleaved. See Section 9.1 for more details.
Alternatively a Transfer Insert can be used in place of the bottom insert in the left fiber holding block. This Transfer
Insert can be used to move the fiber to a Thorlabs Splicer after the fiber is cleaved.
Thumbscrew

LDC450B Large Diameter Cleaver Chapter 3: Description
Page 6 TTN197399-D02
Figure 5 Inserts
3.5. Control Overview
3.5.1. Buttons
The LDC450B fiber cleaver has two buttons: a silver-colored power button in the back and a blue “Start” button in
the front.
•The power button is used for powering up the unit and for turning it off. To turn the unit on, push the power
button for one second. To turn the unit off, push the power button for five seconds.
•The “Start” button is used for initiating cleaves.
3.6. Indicator lights
The LDC450B fiber cleaver has lights on the top surface that indicate the state of the unit. They include:
•A “halo” light in the power button that glows blue when the unit is on
•A “battery level” light that shows how much charge is left in the battery
•A “charging” light that lights up when the battery is being charged.
•A “status” light that changes color based on the state of the unit. The table below indicates the meaning of
the various signals given by the status light.
Status Light Appearance
Meaning
Solid Green
Unit Ready
Flashing Amber
Process Running
Flashing Green
Cleave Complete
Flashing Red
Error
Solid Red
Serious Problem With Circuit Board/Firmware
Dark
Unit Off
Figure 6 Indicator Lights
Transfer Insert

LDC450B Large Diameter Cleaver Chapter 3: Description
Rev A, July 28, 2020 Page 7
3.6.1. Handset Controller
The LDC450B fiber cleaver comes with a Handset Controller that is used for changing parameters and doing
maintenance. It is not required for normal operation of the unit if the proper parameters have been loaded. The
Handset Controller provides a simple,easy to use interface for configuring, controlling and monitoring the LDC450B.
Figure 7 Handset Controller
On power up, the Handset will automatically detect the type of unit it is attached to. This will be displayed at the
top of the screen. Below this will be the names of the available screens with the active screen underlined. You can
access these screens either by pressing on the screen name, or by swiping left or right on the screen.
For a more complete description of the Handset Controller interface and parameters, please refer to Chapter 7.

LDC450B Large Diameter Cleaver Chapter 4: Setup
Page 8 TTN197399-D02
Chapter 4 Setup
4.1. Initial Setup
1. Plug in the AC power cord.
The power supply accepts an AC input of 100-240 VAC; 47-63 Hz.
Do not use a mains supply cord that is rated for less than 1.5A.
2. Connect the AC power cord to the DC power supply.
3. Plug the DC power jack into the unit.
4. If the shipping fixture is still in place, remove it and store it in a safe
place (see section 3.3). Place the bottom insert into the right fiber
holding block. Tighten the set screws to lock it in place.
5. Place the appropriate transfer insert/bottom insert into the left fiber
holding block. Do not tighten the set screws if using a transfer insert.

LDC450B Large Diameter Cleaver Chapter 4: Setup
Rev A, July 28, 2020 Page 9
6. Place the appropriate top insert into the lids of the fiber
holding blocks and tighten the set screws to lock them in place. Note
that the inserts are double-sided, and it may be necessary to flip them
over in order to find the size you are require. Also note that the
setscrews are in the back of the lid (see picture).
7. Locate the USB Y-cable that is included with the unit. Locate
the USB type A plug that is by itself on the long leg of the cable.
8. Plug this USB plug into the top USB socket of the handset (Note
that the USB socket on the side of the handset is dedicated to
connecting a USB flash drive for importing/exporting fiber files and
updating software. Leave it unpopulated for now).
9. Plug the USB Type B plug of the Y-cable into its socket labeled
Data on the back of the unit and plug the USB Type A plug into the
soclet labled Power Out.
4.2. Power-up
To turn on the unit, press the silver button for more than five seconds. The status light will flash orange and the left
fiber holding block will move to the load position. Once the left fiber holding block has moved into the load position,
the LED will emit a steady green light, indicating the unit is ready to cleave. Whenever the unit is on, regardless of
its state, the “halo” of the silver button will glow blue.

LDC450B Large Diameter Cleaver Chapter 4: Setup
Page 10 TTN197399-D02
4.3. Performing the First Cleave
When the status LED is steady green, the unit is ready to perform a cleave. Ensure that the proper inserts are in
place, ensure that the correct parameters have been loaded, and ensure you have stripped and cleaned the fiber
properly.
Place the fiber into the left fiber holding block v-groove, close the lid, and lift the lever so that the lid closes
completely. Make sure the stripped end of the fiber is sitting fully in the right v-groove, close the lid, and lift the
lever. Press the start button.
The LED will start flashing orange indicating that the unit is performing a process. The unit will apply tension to the
fiber, and when the target tension is reached, the cleave blade assembly will start oscillating until it touches the
fiber and performs the cleave. The left fiber holding block will move to the designated pullback position (if it is
engaged) and the LED will flash green indicating that the process has finished. Press down on the left lever, open
the lid, and remove the fiber. Press down on the right lever, open the lid, and remove the fiber remnant from the
right fiber holding block. Press the start button to return the nest to the correct initial starting position.
4.4. Shut-down
To turn the unit off, press the silver button for five seconds. All of the indicator lights will go dark.

LDC450B Large Diameter Cleaver Chapter 5: Theory of Cleaving
Rev A, July 28, 2020 Page 11
Chapter 5 Theory of Cleaving
The LDC450B automated fiber cleaver is designed for cleaving optical fibers with claddings from Ø200 µm up to
Ø1.25 mm. It is possible to cleave smaller fibers as well, but the smaller fibers are more difficult to position correctly
in the v-grooves. For this reason, we recommend the LDC401 and LDC401A fiber cleavers to people wishing to
cleave small-diameter fiber. Both of those models are equipped with a vacuum which sucks the fibers into the v-
grooves during loading.
To produce a flat cleave, the LDC450B uses a “tension-and-scribe” method, whereby an axial tension is first applied
to the fiber followed by an automated Scribe Process utilizing a diamond Cleave Blade.
Figure 8 Maximum stress is in the direction of the fiber axis, and the cleave is perpendicular to the
axis of the fiber
5.1. Specialty Fiber Cleaving Processes
Two additional process capabilities are available on the LDC450B. These processes are primarily utilized for
cleaving specialty fibers such as microstructured fiber, highly stressed fibers (MM and PM), or capillary tubing. The
specialty fiber processes are used to produce flat cleaves and improve end face quality but require the execution
of additional steps.
1. Subcritical Process
The “Subcritical Process” applies a tension that is lower than required for a “standard” cleave. The blade
then scribes the fiber, and the tension is slowly (and incrementally) increased to propagate the scribe and
produce the cleave.
2. Micrometer Backstop
The flat surface of the micrometer end acts as a backstop for the fiber during the Cleave Process. When
using the Micrometer Backstop, it is possible to reduce the tension applied to the fiber.
Both of these processes will be described in greater detail in the next chapter.

LDC450B Large Diameter Cleaver Chapter 6: Cleaving
Page 12 TTN197399-D02
Chapter 6 Cleaving
6.1. Overview
The LDC450B cleaves fiber using the tension-and-scribe technique as follows:
1. A stripped fiber is secured in Fiber Holding Blocks (FHBs).
2. The left FHB moves to the left, tensioning the fiber.
3. A diamond-coated blade approaches the fiber and makes a small scribe.
4. The tension causes the scribe to propagate through the fiber, resulting in a cleave.
Figure 9 System Overview
This chapter provides an in-depth description of the manner in which fiber is cleaved using the LDC450B fiber
cleaver.
6.2. The Cleave Process
The cleaver utilizes two Fiber Holding Blocks (FHBs) to securely clamp and position the fiber prior to cleaving. The
left FHB has a linear drive mechanism for applying tension to the fiber. The right FHB is stationary. A load cell is
incorporated into the left FHB for monitoring fiber tension. Once the fiber is positioned and securely clamped in the
FHBs, an automated Cleave Process can be initiated by pressing the “Start” button.
Parameters that can be adjusted using the Handset Controller are shown below in bold. Descriptions of these
parameters are provided in section 7.3.1. The majority of Users will only need to set the Fiber Diameter (cladding),
Cleave Tension, and Pre-Cleave Advance while leaving the rest of the Parameters set to their default values.
The Cleave Process proceeds as follows:
1. The left FHB slowly pulls to the left until the specified Cleave Tension is reached.
2. While the fiber is held under tension, the diamond blade advances towards the fiber. After the blade has
traveled the Blade Offset + Pre-Cleave Advance distance, it begins oscillating towards the fiber in small
back-and-forth steps. As soon as the diamond blade contacts the fiber it creates a small scribe, which
rapidly propagates through the fiber due to the pre-applied tension.
3. When the fiber is cleaved, the cleaver senses the drop in tension and immediately draws the cleave blade
back and the left FHB pulls further left to move the fiber held within it away from the waste piece.
These cleavers are configured such that the cleave “off-cut”(the piece of fiber that is discarded) is on the right. It is
possible to use the cleaver the ‘other way around’, such that the off cut is on the left hand side of the machine.
FHB Lid
Cleave
Blade
Fiber Holding
Block (FHB)
Micrometer
Backstop
Ruler Block
Lifting
Lever

LDC450B Large Diameter Cleaver Chapter 6: Cleaving
Rev A, July 28, 2020 Page 13
While it is typically preferable to clamp directly on the cladding (bare glass) on the discard side, it is also possible
to center-strip the fiber and to clamp on the buffer. This may be advantageous for certain types of non-circular fiber
that would otherwise rotate uncontrollably during clamping. The “non-discard” side (passing through the left-hand
FHB) should be clamped on the coating whenever possible to avoid potential damage to the glass. The fiber should
be clamped working from one side of the machine to the other. That is to say, if the “non-discard” (left) side is
clamped first, prior to the “discard” (right) side, then all operations should be carried out on the left side before
securing the right side, to minimize the possibility of twisting the fiber during clamping, which would introduce torsion
in to the fiber, and therefore uncontrolled angle.
Figure 10 Two Pieces of Fiber after a Cleave
It is critical that the Cleave Tension be set appropriately for the fiber being cleaved. If the tension is set too low,
the fiber may not cleave and the diamond blade could be damaged due to excessive lateral stresses as the fiber
flexes around the blade. If the tension is too low and the fiber does cleave, the cleave quality will not be very good.
The cleave angle is likely to be high. If the Cleave Tension is set too high, the fiber may break at the clamping
points prior to reaching the desired tension, or, if the cleave is successful, the end face may have excessive
“misting”, fracturing and/or roughness.

LDC450B Large Diameter Cleaver Chapter 6: Cleaving
Page 14 TTN197399-D02
6.3. The Fiber Holding Blocks, Inserts, Lifting Levers, and Thumbscrews
The Fiber Holding Blocks (FHBs) are designed to accommodate a wide range of fiber buffer and cladding sizes
through the use of changeable top and bottom fiberholder inserts, which must be purchasedseparately. The bottom
inserts feature V-grooves and are available in three varieties. Insert options are outlined in the table below. The
VHD and VHF series of bottom inserts feature holes for vacuum to assist in loading the fiber when used in other
equipment such as the GPX family of splicers. The VHF series of Transfer Bottom Inserts are designed to work with
the VHT1 Transfer Clamps to aid in moving the fiber between compatible Vytran stations while maintaining coarse
alignment, allowing safe easy handling, and also providing accurate registration/repeatable lengths of the cleaved
parts. The VHE series of inserts have long extensions that allow the fiber to be held in place by a user’s finger while
the FHB Lid is closed. Both the bottom inserts and the top inserts (which feature flat clamping areas) must be sized
according to the buffer/cladding diameter. Selecting the correct inserts ensures that full cleave tension can be
applied without the fiber slipping. All inserts are labeled with a nominal accepted diameter in microns. In the event
that you wish to use a fiber that is between insert sizes, refer to the chart in Section 9.1 to determine which inserts
would be most suitable or use the Insert Selection tool in Handset Controller.

LDC450B Large Diameter Cleaver Chapter 6: Cleaving
Rev A, July 28, 2020 Page 15
Lifting levers are used to overcome the very high clamping forces of the FHB magnets. To lift the FHB lid, press
down on the lifting lever first, and then lift the Lid. When closing an FHB Lid, make sure that the lever is in the
downward position: this will prevent the FHB lid from slamming down on the fiber, possibly damaging it. After the
lid comes to rest on its lifting lever cam, it can be closed gently by lifting the lever.
Figure 11 A Lifting Lever Propping up the FHB Lid
Figure 12 Lifting Levers and Thumb Screws
Thumbscrews on the FHB lids provide added clamping force for large diameter fibers (>400 µm) or for fibers with
very slippery coatings requiring additional clamping force. If the thumbscrews are not required, they may be kept
out of the way by threading them backwards into the lids or by removing them completely.
Note that when the thumbscrews are used, the user should be sure that they are undone when operating the lifting
levers to open the FHB Lid.
Also note that thumbscrews are not a substitute for correctly chosen and fitted FHB inserts!
The normal clamping force created by the magnets may be excessive for some applications involving very delicate
fiber (e.g. thin-walled capillary tubes and PCF). If the lids crush the fibers, it will be necessary to reduce the clamping
force. This can be achieved by pushing out the magnets in the lids with a stick, or pulling them out with a rare-earth
magnet. It is prudent to mark one side of the magnets before removal so the orientation and position are easily
identified. After completing work on the delicate fiber, remember to return the magnets to the lid holes facing the
correct direction. They should all be attracted to, not repelled by, their counterparts in the FHB body. The polarity
Thumbscrews
Lift levers to
permit lids to
close fully

LDC450B Large Diameter Cleaver Chapter 6: Cleaving
Page 16 TTN197399-D02
of these magnets alternates, and can most easily be determined by a rod-shaped magnet that is easy to hold
between two fingers.
6.4. Stripping the Fiber
The fiber end should be stripped down to the cladding over a sufficient length to allow for the desired post cleave
length plus the discard length. The discard length should ideally allow for full clamping in the FHB, and should
therefore be 1.8″ (45 mm). A Ruler Block is provided for accurate positioning of the strip interface relative to the
cleave point. The fiber must be stripped down to bare glass and thoroughly cleaned at the location where the
diamond blade strikes the fiber (the cleave point).
Figure 13 Stripping Fiber using a Miller Stripper
6.5. Loading the Fiber
To load the fiber for cleaving:
1. Make sure that the correct Cleave File (Fiber File) and/or process parameters are selected for the fiber to
be cleaved (see Section 7.4). If necessary, the critical parameters can be estimated using the Auto
Parameter Tool in the Handset Controller.
2. If the FHB lids are closed, loosen the thumbscrews, press the lifting levers down to release the clamping
force and open the lids.
3. Check that the correct FHB inserts (top and bottom) are installed and that they are free from fiber and/or
coating debris. Position the fiber in the left-hand FHB V-groove with the stripped (discard) end positioned
in the right-hand V-groove.