Document Outline
- Features
- Applications
- Description
- Absolute Maximum Ratings
- Performance Specifications
- Fiber Pigtail
- Reliability Target
- Example of LST242X All dimensions in mm.
- LST3421 Specification All dimensions in mm.
- Ordering Information
514
Coaxial Pigtailed Laser Module
Preliminary Technical Data
LST2425X, LST3421X
Features
Compact Coaxial Package
Strained Multi Quantum
Well Distributed Feedback
(DFB) Laser Chip
Low Thresholds Current and
Operating Currents
Wide Operating Tempera-
ture -40
C to +85
C
Excellent Wavelength
Stability with Temperature
~0.1 nm/
C
Narrow Line Width
<1 nm @ -20 dB
Side Mode Suppression
Ratio >-30 dB
Modulation Capability up to
622 Mb/s
Convenient Variety of
Pinout and Mounting Flange
Options
Applications
Telecommunications
Fiber in the Loop
Inter/Intra Office
SONET/SDH
Datacommunications
Switches
Description
Products in the LST242X family
are compact coaxial pigtailed
DFB laser transmitters, operating
in the 1300 nm wavelength
region and coupling light to
single mode fiber. They are
designed for use in short,
medium and long distance
networks with bit rates up to
622 Mb/s.
The device features a high
reliability SMQW-DFB laser diode
and rear facet monitor photo-
diode. These are electrically
connected to four pins in an
industry-standard configuration.
Environmental performance is
designed to be compatible with
the requirements of Bellcore's
TA-NWT-000983 document.
Options within the LST242X
family offer pinouts and pin
rotational orientations designed
to match existing products
available on the market. We also
offer a comprehensive range of
alternative mounting flanges
including a dual in line option.
If the specific arrangement or
performance you require is not
listed, please contact your local
representative as our highly
flexible design and manufacturing
processes allow both physical and
electro-optical customization to
meet your needs.
Preliminary Product Disclaimer
This preliminary data sheet is provided to assist you in the evaluation of engineering samples of the product which is under development
and targeted for release during 1997. Until Hewlett-Packard releases this product for general sales, HP reserves the right to alter prices,
specifications, features, capabilities, function, manufacturing release dates, and even general availability of the product at any time.
Laser Safety Warning
This device is a Class IIIb (3b) Laser Product. It may emit invisible laser radiation if operated with the fiber pigtail disconnected. To avoid
possible eye damage do not look into an unconnected fiber pigtail during laser operation. Do not exceed specified operating limits.
(5/97)
515
Limits
Parameter
Symbol
Test Condition
Min.
Max.
Units
Laser Forward Current
If
DC
120
mA
Laser Reverse Voltage
Vlr
DC
2
V
Photodiode Reverse Voltage
Vr
DC
20
V
Photodiode Forward Current
Ipf
DC
1
mA
Operating Temperature
A
Tc
Temperature measured at case
40
+85
C
B
0
+70
C
Storage Temperature
Ts
40
+85
C
Relative Humidity
RH
noncondensing
%RH
Fiber Pull Strength
Three times; 10 sec.
10
N
Mechanical Shock
MIL-STD-883D, Method 2002,
500
G
Condition A
Vibration
MIL-STD-883D, Method 2007,
20
G
Condition A
Absolute Maximum Ratings
Absolute limiting (maximum) ratings mean that no catastrophic damage will occur if the product is subjected to these ratings for short periods,
provided that each limiting parameter is in isolation and all other parameters have values within the performance specification. It should not be
assumed that limiting values of more than one parameter can be applied to the product at the same time.
Performance Specifications
LST242X
LST3421
Parameter
Symbol
Test Condition
Min.
Max.
Units
LASER
CW, over operating temperature
range, Po, as noted below unless
otherwise stated and 20 dB ORL
Rated Optical Power
Po
Tc = ranges specified above, CW
2
mW
Threshold Current
Ith
Tc = +25
C
4
15
mA
Threshold Current
Ith
Over operating temperature range
2
40
mA
Coupled Power in "Off" State
Pth
If = Ith 2 mA
0
10
W
Drive Current above Ith,
Id
Tc = +25
C
12.5
25
mA
Over operating temperature range
-
40
mA
Forward Voltage
Vf
1.6
V
Center Wavelength
Over operating temperature range
1280
1335
nm
Wavelength/Temperature
/
T
0.1
nm/
C
Coefficient
Spectral Width
At 20 dB
1
nm
Side Mode Suppression Ratio
SMSR
+30
dB
Rise and Fall Time
10-90%, Ith to Po
0.5
ns
MONITOR PHOTODIODE
Tc = +25
C, Vr = 5 V,
Po = Rated Power
Photocurrent
Im
50
1000
A
Dark Current
Id
Po = 0
W
20
nA
Capacitance
C
1 MHz
10
pF
Tracking Error
R
Im = Im (Po, +25
C)
1
1
dB
Tc + 40
C to + 85
C
for Im = Im (Po, +25
C)
516
Fiber Pigtail
Parameter
Minimum
Maximum
Units
Fiber Pigtail Length
1000
mm
Spot Size (Mode Radius)
4.5
5.5
m
Cladding Diameter
122
128
m
Core/Cladding Concentricity
1
m
Secondary Jacket Diameter
0.8
1
mm
Effective Cutoff Wavelength
1150
1240
nm
Reliability Target
Parameter
Condition
Min.
Max.
Units
Median Life
50% inc. in total drive current, Tc = +25
C
2x10
5
hours
517
H
N
I
L
M
F
K
G
P PIN DIAMETER
R
J
Q
B
C
O
A
D
OTHER FLANGE OPTIONS ARE AVAILABLE.
MIN.
TYP.
MAX.
11.8
2.4
12.5
7.4
17.0
3.7
12.2
2.6
12.9
A
B
C
D
E
F
MIN.
TYP.
MAX.
12.0
2.1
5.3
2.0
1000
20.0
2.3
G
H
I
J
K
L
DIM.
DIM.
MIN.
TYP.
MAX.
0.4
0.9
5.3
2.0
0.5
1.25
0.5
M
N
O
P
Q
R
DIM.
E
Example of LST242X
All dimensions in mm.
FUNCTION
MONITOR ANODE (-VE)
MONITOR CATHODE (+VE)
LASER CATHODE (-VE)
LASER ANODE (+VE)
1
2
3
4
PIN
4
1
3
2
CASE
LASER
LST2425
518
A
B
C
D
H
TYP.
12.60
7.62
2.54
30.00
A
B
C
D
DIM.
4
3
2
1
5
6
7
8
C/L
E
PIN 1 INDICATOR
F
I
G
4
3
2
1
5
6
7
8
PHOTODIODE
LASER
CASE
FUNCTION
NO CONNECTION
MONITOR ANODE (-VE)
MONITOR CATHODE (+VE)
NO CONNECTION
NO CONNECTION
LASER CATHODE (-VE)
LASER ANODE (+VE)
1
2
3
4
5
6
7
PIN
(CONNECTED TO HEADER)
NO CONNECTION
8
TYP.
10.20
12.60
4.26
3.53
E
F
G
H
DIM.
NOTE:
PINS 1, 4, 5 AND 8 ARE ISOLATED
FROM THE INTERNAL CIRCUITRY,
BUT ARE ELECTRICALLY CONNECTED
TO EACH OTHER.
PINS 1, 4, 5, & 8 0.51 x 0.38 NOM.
PINS 2, 3, 6, & 7 0.4/0.5 DIA.
K
J
TYP.
2.54
8.60
3.20
I
J
K
DIM.
OPTION 1
LST3421 Specification
All dimensions in mm.
PDF 
ZIP