TECHNOLOGI

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MBC-DG seriesContinuously Tunable Modulator Bias Controllers

SDelivering Modulation Solutions
Bias Controllers
Photline Technologies MBC are a family of automatic bias controllers speciallydesigned to lock the operating point of LiNb03 Mach-Zehnder modulators andensure a stable operation over time and environmental conditions.
MBC controllers are continuously tunable bias controllers, meaning they allow
operation of the modulator at any point of its transfer function and thus can beused for a large variety of applications. They are easy to implement, and areavailable as bench top instruments and OEM boards.
MBC-DG series controllers are especially well suited for digital and pulse
applications, when MBC-AN series are optimized for analog applications.

Features• Designed for Mach-Zehnder
modulators• Min, Max, Quad modes and anyother operating point

Principle
MBC-DG controllers are dither signal based : a low amplitude, low frequency
tone signal is superimposed to the modulation signal. The resulting opticalmodulation is then detected and a digital signal processing based on a FFT
analysis principle allows to lock the operating point at the desired position.

• High sensitivity < 30 dBm• High stability

Applications

Performance Highlights• LiNbO3, InP, GaAs modulators

ParameterMinTypMaxUnit• Digital NRZ, RZ, QPSK modulators
polarization

DC bias voltage-10-+10V

Input current

3-

500mA

Locking range-360-

Degree9090.5DegreeER ± 0.05-dB• Analog applications• Pulse applications

Locking accuracy at Quad±Extinction ratio at MIN mode

Options

189.5
1ER : modulator nominal Extinction Ratio value• Internal photodiode and tap coupler• Bench-top and board versions• Ditherless version for sensitive
analogue applications

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MBC-DG seriesContinuously Tunable Modulator Bias Controllers

SBias Controllers
Electrical Characteristics
Parameter
DC bias voltage

Input photocurrent

Photocurrent dynamic range

SymbolCondition

Min

TypMax

UnitVbias

by 0.1 V bias voltage step-10-+10V

total range over 4 user selectable gains

3-

500mA

gain 1

100-

500mA

gain 2

20-

200mA

gain 310-

100mA

gain 43-30mA

total range over 4 user selectable gains-22-

dBrange over 1 user selectable gain

7810dB

TypMaxUnit

2 000nm

Iph

DIph

Optical Characteristics
Parameter

SymbolConditionMin

Wavelengthl-

780

Input optical power

PIN

with internal PD and tap coupler option

--4-

dBm

total range over 4 user selectable gains &with internal PD and tap coupler option

-22-

dBm

range over 1 user selectable gain
with internal PD and tap coupler option

-8-

dBm

Optical dynamic range

DPIN

Bias Control Characteristics
Parameter

2Symbol

ConditionMinTypMax

Unit

Locking range

DQ

by manual & automatic control-360-

DegreeLocking accuracy

Qat Quad±

89.5

9090.5DegreeExtinction ratio

ERMIN mode, with proper modulator andwith internal PD and tap coupler option

50 2dB

Extinction ratio stability

SER

MIN mode, with proper modulator andwith internal PD and tap coupler option,over 1 hour-± 0.05-dB

Dither frequency

fditherby 40 Hz frequency step

400-

1 400

Hz

Dither amplitude

Vditherby 10 mV amplitude step50-

1 000Vthe modulator must show a ver y high Extinction Ratio value

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TECHNOLOGIESMBC-DG seriesContinuously Tunable Modulator Bias Controllers

Bias Controllers
MBC-DG-BT - Bench-top version
The MBC-DG-BT is a bench-top instrument. Its intuitive front pannel allows to adjust the bias control parameters : dithering amplitude and frequency, operating point position on the transfer curve... so as to optimize the modulated opticalsignal and its stability. Different digital modulation formats (NRZ, RZ, DPSK) require specific operating points and biascontrol parameters. That is also true for pulse signals with different duty cycles.
The MBC-DG-BT can operate with a photocurrent signal delivered by a user provided photodiode or from an optional
internal photodiode / tap coupler set (OPT-PD/TAP-wwww). It comes with a RS-232 interface and a LabView driver for
virtual instrument remote control.
Using an internal monitoring photodiode: the advantage of this scheme is it avoid the optical losses due to a tapping
coupler. Moreover the set up is more compact than the one using an external fiber coupler.

Dimensions
Dimensions (W x H x D)

24 cm x 8.5 cm x 16 cm

WeightPower supply (rear panel)

1.5 kg - 3.3 pounds
100-120 V / 220-240 V automatic switch, 50-60
HzInterfaces
Bias voltage output

2 mm jack (cables supplied)

Photocurrent input

2 mm jack (cables supplied)

Optical input (with OPT PD/TAP)

FC/PC bulkhead

Remote Control
Type

RS-232 or USB with Labview driver

Connector

Sub-D 9 pins / USB type B

Ordering information
Bench-top Modulator Bias Controller MBC-DG-BT
Photodiode and tap coupler set, 800 nm region OPT-PD/TAP-800
Photodiode and tap coupler set, 1000 nm region OPT-PD/TAP-1000
Photodiode and tap coupler set, 1300-1550 nm region OPT-PD/TAP-1550
USB option for remote interface OPT-USB

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MBC-DG seriesContinuously Tunable Modulator Bias Controllers

Bias Controllers
MBC-DG-board : OEM version
The MBC-DG-board is an OEM board designed for integration in systems and comes with an embedded intensity
modulator. The MBC-DG-board offers a similar performance than the MBC-DG-BT bench top instrument. The bias control
parameters of the board can be adjusted through the RS-232 interface. A LabView driver is supplied with the board,as well as the complete communication protocol.

Parameter
160 mm x 100 mm x 27 mm

Supply voltages+12 / -12V / +5 V

Remote control

RS-232 with LabView driver

Connector

Sub-D 9 pins

V1, PT-Q1-2009

Dimensions (L x W x H)

Ordering information
Board Modulator Bias Controller MBC-DG-Board
Photodiode and tap coupler set, 800 nm region OPT-PD/TAP-800
Photodiode and tap coupler set, 1000 nm region OPT-PD/TAP-1000
Photodiode and tap coupler set, 1300-1550 nm region OPT-PD/TAP-1550

About us
Photline Technologies is a provider of Fiber Optics Modulation Solutions based on the company LiNb03 modulatorsand high-speed electronics modules. Photline Technologies offers high speed and high data rate modulation solutions
for the telecommunication industry and the defense, aerospace, instruments and sensors markets. The products
offered by the company include : comprehensive range of intensity and phase modulators (800 nm, 1060 nm, 1300nm, 1550 nm), RF drivers and modules, transmitters and modulation units.
Photline Technologies reserves the right to change, at any time and without notice, the specifications, design,function or form of its products described herein. All statements, specification, technical information related
to the products herein are given in good faith and based upon information believed to be reliable andaccurate at the moment of printing. However the accuracy and completeness thereof is not guaranteed. No
liability is assumed for any inaccuracies and as a result of use of the products. The user must validate all parameters for each application before use and he assumes all risks in connection with the use of the products.

ZI Les Tilleroyes - Trépillot
16, rue Auguste Jouchoux - 250000 Besançon - FRANCEtél. : +33 (0) 381 853 180 - fax : + 33 (0) 381 811 557
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