Document Outline
- Features
- Applications
- Description
- Absolute Maximum Ratings
- Performance Specifications
- Fiber Pigtail
- Reliability
- Other documentation
- Example of LST2x25
- Ordering Information
- Laser Warning
- CDRH Certification
155/622 Mb/s SMQW Pigtailed
Laser Modules
Technical Data
LST2525 - 200 W Coaxial Laser
LST2825 - 1 mW Coaxial Laser
Features
Strained Multi Quantum
Well (SMQW) Fabry Perot
laser chip
Low threshold and
operating current
Wide Operating
Temperature Range
Optical Power up to 1 mW
Modulation Capability up to
622 Mb/s
Applications
Telecommunications
Fiber in the loop
Inter/lntra Office
SONET/SDH
Datacommunications
Switches
Description
Products in the SMQW pigtailed
laser module family consist of a
coaxial style package 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 Fabry Perot
laser diode and rear facet monitor
photodiode. 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.
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.
Laser Safety Warning
This device is a Class IIIa (3a) 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.
2
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings can cause catastrophic damage to the device. Limits apply to each parameter in isolation,
all other parameters having values within the recommended operating conditions. It should not be assumed that limiting values of more than one
parameter can be applied to the product at the same time. Exposure to the absolute maximum ratings for extended periods can adversely affect
device reliability.
Performance Specifications
Parameter
Symbol
Test Condition
Limits
Unit
Min.
Max.
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
Tc
Temperature measured at case
-40
+85
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-883E, Method 2002, Condition A
500
G
Vibration
MIL-STD-883E, Method 2007, Condition A
20
G
Parameter
Symbol
Test Condition
LST2525
LST2825
Unit
Min.
Max.
Min.
Max.
LASER
CW, Tc = -40C to +85C,
Po as noted below
unless otherwise stated
Rated optical power
Po
Tc = ranges specified
above, CW
0.2
1
mW
Threshold current
Ith
Tc = +25C
3.5
10
3.5
10
mA
Threshold current
Ith
1.5
30
1.5
30
mA
Coupled Power in "Off"
state
Pth
If = Ith - 2 mA
12
12
W
Slope efficiency
h
Tc = +25C
10
16
50
100
W/mA
Drive current above Ith,
for Im = Im (Po, +25C)
Id
Tc = +25C
12.5
20
10
20
mA
Tc = -40C to +85C
10
33.3
7.5
33.3
mA
Forward voltage - LST
Forward voltage
- HFCT
Vf
1.6
1.6
V
3.0
3.0
V
Centre wavelength
l
Tc = +25C
1286
1336
1286
1336
nm
Tc = -40C to +85C
1260
1360
1260
1360
nm
Wavelength/temperature
coefficient
Dl/DT
0.4
0.4
nm/C
Spectral width
s
One sigma, RMS
2.5
2.5
nm
Rise and fall time
t
10 - 90%, Ith to Po
380
380
ps
3
Performance Specifications (Continued)
Fiber Pigtail
Reliability
Other documentation
SMQW Laser Diode Reliability Datasheet
Publication number 5965-1293E
LST252X/LST282X Qualification Report
Publication number 5965-8894E
Parameter
Minimum
Maximum
Unit
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
Parameter
Condition
Minimum
Maximum
Unit
Median Life
50% inc. in total drive current, Tc = +25C
2 x 10^5
hours
Parameter
Symbol
Test Condition
LST2525
LST2825
Unit
Min.
Max.
Min.
Max.
MONITOR
PHOTODIODE
Tc = +25C Vr = 5 V,
Po = Rated Power
Photocurrent
Im
200
1000
200
1000
A
Dark current
Id
Po = 0 W
20
20
nA
Capacitance - LST
Capacitance
- HFCT
C
1 MHz
10
10
pF
20
20
pF
Tracking Error
DR
Im = Im (Po, +25C) Tc +
-40C to +85C
1
1
dB
Rise and fall time
tr
10 - 90%, Ith to Po
2
2
ns
4
Example of LST2x25 -
All dimensions in mm.
LST2x25
CASE
1
2
3
4
LAS
E
R
P
HOT
ODI
ODE
LST2x25
Pin
Function
1
Monitor Anode (-ve)
2
Monitor Cathode (+ve)
3
Laser Cathode (-ve)
4
Laser Anode (+ve)
Dimension
Min. Typ. Max.
Dimension
Min. Typ. Max.
Dimension
Min. Typ. Max.
A
7.4
G
12
M
0.9
B
17
H
20
N
5.3
C
11.8
12.2
I
5.3
O
2
D
3.7
J
2
P
0.4
0.5
E
2.4
2.6
K
2.1
2.3
Q
0.5
F
12.5
12.9
L
1000
R
1.25
A
C
O
B
D
E
F
G
H
I
J
K
L
M
N
P - Pin diameter
Q
R
5
Ordering Information
Coaxial Package
LST2x25-x-xx
Connector Type:
FP = FC/PC
SC = SC
ST = ST
Flange:
T = Universal flange
Power:
5 = 200 W
8 = 1 mW
Available options:
LST2525-T-FP
LST2825-T-FP
LST2525-T-SC
LST2825-T-SC
LST2525-T-ST
LST2825-T-ST
ST
is a Registered Trademark of AT&T
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