Data
sheet
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Thinking optical solutions
Continuous Wave
Fixed Wavelength
Laser 20mW
Offering 20mW CW output power, the Continuous Wave
Fixed Wavelength Laser -20mW is a wavelength stabilised
DFB laser suitable for deployment in high speed, DWDM
applications with 50 GHz channel spacing.
Incorporating a Fabry-Perot etalon and two monitor photodiodes,
the CW laser may be "locked" to the ITU grid and wavelength
can be maintained to within +/-20pm over temperature and life.
The laser is supplied in a 14 Pin butterfly package with a polarisation
maintaining, single mode fibre pigtail (Fujikura PANDA type).
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Features
Built-in Fabry-Perot etalon and
dual InGaAs PIN photodetector
array allows wavelength stabilised
operation to within 20pm
over life.
ITU wavelengths available from
1530nm to 1605nm.
InGaAsP Distributed Feedback
(DFB) single frequency laser chip.
Polarisation maintaining single
mode fibre.
Hermetically sealed 14 pin
butterfly package with optical
isolator.
Integral thermo-electric cooler
with precision thermistor.
Applications
SONET/SDH, OC48/STM-16,
OC192/STM-64 systems
Long and very long reach DWDM
Networks Transmitters using
a LiNb03 external modulator.
Parameter
Conditions/Symbol
Min
Typ
Max
Unit
Optical Output Power
P
o
20
mW
Operating Current
L
op
175
220
mA
Threshold Current
20
40
mA
Forward Voltage
V
f
1.7
2.7
V
Peak Wavelength Ageing
-20
20
pm
Peak Wavelength SOL
-40
ITU grid
40
pm
Side Mode Suppression
L
op
37
dB
Spectral Width
2
10
MHz
PIN Photocurrent
L
m
4
mA
Locking PIN Photocurrent
L
lock
0.2
2
mA
PIN Dark Current
100
nA
PIN Spectral Response BW
0.2
0.8
nm
PIN Response Peak Spacing
0.35
nm
Locking Ratio
L
lock
/l
peak
40
80
%
Thermistor Resistance
6.7
14.5
kOhm
Heatpump Current
Case Temp = 70
C
1.4
A
Heatpump Voltage
Case Temp = 70
C
3
V
Polarisation Extinction Ratio
20
dB
Characteristics
Conditions unless otherwise stated: PIN detector bias: -5V
Optical Back Reflection: -20dB
Absolute Ratings
Table 1: Characteristics
Parameter
Conditions/Symbol
Min
Typ
Max
Unit
Case Operating Temperature
0
70
C
Storage Temperature
-40
85
C
Laser Bias Current
275
mA
Laser Reverse Voltage
2
V
PIN Photodiode Reverse Bias
15
V
Fibre Bend Radius
35
mm
Table 2: Absolute Ratings
Typical Performance Characteristics
Figure 1: Typical Performance Characteristics
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Instructions for Use
Pin 1, 2, 4, 11, 13, 14 Package Ground
Ground all pins for optimum performance.
Pin 3 TEC (+) and Pin 12 TEC (-)
Applying a positive voltage on pin 3 with respect to pin 12
will cause the internal components (or laser submount) to
be cooled relative to the case temperature. Reversing the
applied voltage will cause them to be heated. The power
supply for the TEC should be capable of sourcing up to
1.4A at 3V. Note that heating the internal components (or
laser submount) to greater than 85C may cause
permanent damage to the laser module.
Pin 5 laser Bias (-) Cathode and Pin 10 Laser Bias (+)
Anode
Laser bias current is applied via these pins, both of which
are floating with respect to ground. The laser is operated
with a forward bias current up to 220mA at 2.7V(max).
Pin 6 Thermistor
The Thermistor is used in the control loop for keeping the
internal temperature at a constant value. It has a nominal
resistance of 10k (at the typical operating at 25C) and is not
polarity sensitive. Operating current should be limited to less
than 100A to prevent self-heating errors. The exact
thermistor value will be supplied with the device to ensure
correct operating wavelength. The other side of the
thermistor is internally connected to case ground.
Pin 7 Monitor Anode (short), Pin 8 Monitor Anode
(Long) and Pin 9 Monitor Cathode
The two back facet monitor diodes are used in a control
loop, which maintains constant laser wavelength. Each
diode has a different spectral response, which overlaps at
the "locked" wavelength. The control loop can control
submount temperature and/or laser bias current to
maintain the two monitor diode currents at equal values,
corresponding to the locked wavelength. The diode
cathodes are commoned on pin 9 and are operated with
reverse 5V bias.
Outline Drawing
Dimensions in mm
Figure 2: Outline drawing
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REFERENCE IEC 608251: Edition 1.2
INVISIBLE LASER RADIATION
DO NOT VIEW DIRECTLY
WITH OPTICAL INSTRUMENTS
CLASS 1M LASER
THIS PRODUCT COMPLIES WITH 21CFR 1040.10
DANGER
INVISIBLE LASER RADIATION -
AVOID DIRECT EXPOSURE TO BEAM
OUTPUT POWER 80 mw
WAVELENGTH >1520 nm
Class III b Laser Product
CAUTION
STATIC SENSITIVE DEVICE
OBSERVE PRECAUTIONS
Certificate No. FM 15040
Certificate No. EMS 35100
Ordering Information
Order Code No. LC155CDC****-20
Where **** = Last four digits of wavelength value i.e. for 1545.32nm **** = 4532
For wavelength information see Bookham Technology's WDM wavelength plan.
The fibre pigtail is terminated with a 2.5mm o.d. ferrule.
Connections
Table 4: Connections
Pin 1
Ground
Pin 14
Ground
2
Ground
13
Ground
3
TEC (+)
12
TEC (-)
4
Ground
11
Ground
5
Laser cathode
10
Laser anode
6
Thermistor
9
PIN cathode
7
PIN short anode
8
PIN long anode
Figure 3: Connections
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REV 1 Feb 2003
Bookham Technology 2003 Bookham & ASOC are registered trademarks of Bookham Technology plc
North America
Bookham Technology Inc.
49 Buford Highway
Suwanee
GA 30024
USA
Tel: +1 678 482 4021
Fax: +1 678 482 4022
Europe
Bookham Technology plc
Brixham Road
Paignton
Devon
TQ4 7BE
UK
Tel: +44 (0) 1803 66 2875
Fax: +44 (0) 1803 66 2801
Asia
Bookham Technology plc
21/F Cityplaza One
1111 King's Road
Quarry Bay
Hong Kong
Tel: +852 (2100) 2249
Fax: +852 (2100) 2585
Sales@bookham.com
Important Notice
Bookham Technology has a policy of
continuous improvement, as a result
certain parameters detailed on this flyer
may be subject to change without notice.
If you are interested in a particular product
please request the available from any
Bookham Technology sales representative.
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