iXBlue MBC-AN-LAB User manual

MBC-AN-LAB
Operating Manual Version 2.0

MBC-AN-LAB 1 Version 2.0
Content
Legal Notice..............................................................................3
Disclaimers........................................................................................................................ 3
About this Manual ....................................................................3
Purpose............................................................................................................................. 3
Audience........................................................................................................................... 3
Prerequisites ..................................................................................................................... 4
Terms and Symbols in this Manual.................................................................................... 4
Electrical safety................................................................................................................. 4
Contacting iXblue .............................................................................................................. 4
General Information .................................................................5
Product Overview.............................................................................................................. 5
Principle of operation......................................................................................................... 5
Standard Specifications..................................................................................................... 7
Panel features...........................................................................8
Front panel.................................................................................................................... 8
Back panel..................................................................................................................... 9
Getting started..........................................................................9
Standard Accessories........................................................................................................ 9
Installation and set up........................................................................................................ 9
Operation.................................................................................10
Quick start procedure.......................................................................................................10
Remarks:..........................................................................................................................12
Calibrating the board........................................................................................................13
Appendices.............................................................................17
A. Mach-Zehnder intensity modulators..........................................................................17
B. Drift effects ...............................................................................................................18

MBC-AN-LAB 2 Version 2.0

MBC-AN-LAB 3 Version 2.0
Legal Notice
Disclaimers
No warranty: This documentation is provided « as is » without any express or implied
warranty of any kind.
Limitation of Liability: Photline does not assume any liability arising out of the
application or use of any products, or software described herein. In no event shall Photline
be liable for any damage whatsoever (including, without limitation, consequential or
incidental damages, damages for lot of profits, or otherwise) arising out of the use of the
information provided in this documentation.
The content of this publication has been carefully checked for accuracy. However,
Photline makes no warranty as to the completeness, correctness, or accuracy of the
information contained within this documentation. In the interest of continued product
improvement, Photline further reserves the right to make any change in any products
describers herein without notice. This publication is subject to change without notice.
About this Manual
Purpose
The purpose of this instruction manual is to explain how to set up the MODBOX and
to utilize the various features of the product.
Audience
This manual is aimed at professionals with the necessary technical background and
prerequisites needed to use fiber optics equipment, including lithium niobate modulators, and
the related tests equipment and accessories.

MBC-AN-LAB 4 Version 2.0
Prerequisites
Reader is assumed to be familiar with and fiber optics technology.
Terms and Symbols in this Manual
The following terms and symbols may appear throughout this manual:
WARNING: Warning statement identifies conditions or practices that could result in injury or
loss of life.
CAUTION: Caution statement identify conditions or practices that could result in damage to
this product or other property
Electrical safety
WARNING
Operate under the proper environmental conditions
The MBC-AN-Board is designed for indoor use. To avoid injuries, do not
expose this instrument to water or excessive moisture. Do not operate the
board in the presence of flammable gases or fumes.
Contacting iXblue
For application oriented or service related requests, please contact iXblue customer
service department:
[e-mail]

MBC-AN-LAB 5 Version 2.0
General Information
Product Overview
MBC-AN-Board is a bias controller specially designed to lock the operating point of a LiNbO3
Mach-Zehnder modulator by monitoring the bias voltage applied on the DC electrodes of the
device.
Unlike classical dither signal based bias controllers, MBC-AN-board does not superimpose
any tone signal to the optical modulated signal. It is designed for application where such a
tone signal is not desired and typically for analog applications where a high purity carrier is
required.
Principle of operation
The MBC-AN bias controller is based on the comparison of the optical power before and
after the Mach-Zehnder modulator. It uses optical tap couplers and photodiodes with
a proportional integrator feedback loop to lock the operating point of the modulator at the
Quad+ or Quad- position.
The MBC-AN-BT is operated with a user supplied PC. It comes with a Windows graphical
user interface.
Figure 1: basic scheme of a modulation set-up including a modulator bias controller and 2 external
monitoring photodiodes

MBC-AN-LAB 6 Version 2.0
A fiber coupler with a strong imbalance (10:90 or 1:99) is placed between the Mach-Zehnder
modulator and the laser. At the output of the coupler a photodiode is used to monitor the
average optical power emitted by the laser. The RF signal is applied to the RF electrodes. At
the output of the MZ modulator, a fiber coupler with a strong imbalance (10:90 or 1:99)
allows to detect a small portion of the transmitted light thanks to a monitoring photodiode.
The signal from the photodiode is amplified and compared with the signal coming from the
laser monitoring photodiode. The discrepancy between both signals are integrated and
injected into the DC electrodes of the modulators in order to maintain the operating point at
the desired position.
The principle of operation of the MBC-AN is based on a proportional integrator feedback
loop. It has been design only for locking the operating point at Quad+ or Quad-.

MBC-AN-LAB 7 Version 2.0
Standard Specifications
Input Signals Specifications
Units
Min
Typ
Max
Electrical
Modulator Bias voltage
V
-12
+12
Photodiode Bias Voltage
V
-5
Bias voltage step (in manual mode)
V
0.002
0.01
Locking point (Transfert level)
QUAD-(-50%), QUAD+(+50%)
Environmental
Operating temperature
°C
+10
+45
Storage Temperature
°C
-40
+75
Power supply
Positive bias voltage
V
0
+12
+15
Negative bias voltage
V
-15
-12
0
90-250V, 50/60Hz AC power supply
Provided
Interfaces
Photodiode Input /coupler input
FC/APC connector
Bias Output
BNC Female connector
Communication
USB Connector
Environmental
Operating temperature
°C
+10
+45
Dimensions
LAB
220 x 220 x 52mm3
Software (GUI)
Minimum computer requirements
Windows XP SP3
One USB port
Recommended computer configuration
Windows XP SP3
One USB port

MBC-AN-LAB 8 Version 2.0
Panel features
Front panel
<1> Power button
<2> Control LED
Auto: MBC is in Auto Mode
Sat: MBC bias control voltage is saturating
<3> Bias Modulator connector (BNC)
<4>: Laser optical input
Input, fiber from laser output (coupler option)
Input, part of laser power (no coupler option)
<5>: Modulator optical input (optional)
Output of the first integrated coupler, to the input optical fiber modulator
<6>: Modulator optical output
Input, fiber from modulator output (coupler option)
Input, part of modulator output power (no coupler option)
<7>: Signal (optional)
Output of the second integrated coupler, working signal.

MBC-AN-LAB 9 Version 2.0
Back panel
<8> Power supply connector (Jack 3.5mm, 12V 500mA)
<9> USB connector
Getting started
Standard Accessories
User Manual
Interface User Manual
Cord Kit
USB Cord
AC-DC Power Supply
Installation and set up
To set-up the MBC-AN-Board for your application you have to install the MBC-AN control
software.
Preliminary: MBC Interface software installation
Minimum computer requirements:
Windows XP/Vista/7
USB port