F i n i s a r
Confidential and Proprietary © 2013 Finisar Corporation. All rights reserved Rev. A1 Page 1
Product Specification
2.5Gbps, 850nm VCSEL, TO-46 Package
HFE4094-542
PRODUCT FEATURES
• 850nm multi-mode oxide isolated
VCSEL
• Capable of modulation operation from
DC to 2.5Gbps
• TO-46 tilt window metal can
component
• Designed for drive currents between 3-
15mA average
• Packaged with a back monitor
• Un-Attenuated window can
These products are high-performance 850nm VCSELs (Vertical Cavity Surface-Emitting Lasers)
designed for high-speed data communications and packaged with a custom designed power
monitor diode. The power monitor diode can be used with appropriate feedback control circuitry
to set a maximum power level for the VCSEL. These combined features simplify design for high
data rate communication and eye safety.
These products are high radiance VCSELs designed to convert electrical current into optical
power that can be used in fiber optic communications and other applications. As the current
varies above threshold, the light intensity increases proportionally.
These products are designed to be used with inexpensive silicon or gallium arsenide detectors,
but excellent performance can also be achieved with some indium gallium arsenide detectors
(see HFD3081-108 and HFD3081-203 product data sheets).
The low drive current requirement makes direct drive from PECL (Positive Emitter Coupled
Logic) or ECL (Emitter Coupled Logic) gates possible and eases driver design.
These are designed to interface with 50/125 and 62.5/125mm multi-mode fiber. They produce
circularly symmetric, non-astigmatic, narrow divergence beams that, with appropriate lensing,
fiber couple all of the emitter power
PRODUCT SELECTION
Part Number Description
HFE4094-542 Un-Attenuated TO-46 component, VCSEL with Back Monitor
Photodiode, Cathode of VCSEL common with Photodiode Anode
HFE4094-542 Product Specification – Aug 2014
F i n i s a r
Confidential and Proprietary © 2013 Finisar Corporation. All rights reserved Rev. A1 Page 2
I. Absolute Maximum Ratings
Parameter Rating
Storage Temperature -40 to +100°C
Case Operating Temperature -40* to +85°C
Lead Solder Temperature 260°C, 10 sec.
Laser continuous Forward Current 12mA
Laser peak forward current with pulse
width less than 1ms
18mA
Laser Reverse voltage 5V
ESD Exposure (Human Body Model) 225V
1
Notice
Stresses greater than those listed under “Absolute Maximum Ratings”
may cause permanent damage to the device. This is a stress rating
only and functional operation of the device at these or any other
conditions above those indicated in the operations section for
extended periods of time may affect reliability.
Notice
The inherent design of this component causes it to be sensitive to
electrostatic discharge (ESD). To prevent ESD-induced damage
and/or degradation to equipment, take normal ESD precautions when
handling this product
HFE4094-542 Product Specification – Aug 2014
F i n i s a r
Confidential and Proprietary © 2013 Finisar Corporation. All rights reserved Rev. A1 Page 3
II. Electro-Optical Characteristics (T
OP
= 25 °
°°
°C unless otherwise stated)
Notes:
VCSEL Parameters Test Condition Symbol Min. Typ. Max. Units Notes
Optical Power Output I
F
= 7mA P
O
2.0 mW 2
Threshold Current I
TH
0.5 1.8 2.5 mA
Threshold Current maximum
deviation from 25
o
C value
T
A
= 0
o
C to 70
o
C ∆I
TH
-0.5 1 mA 3
T
A
= 25
o
C to 85
o
C ∆I
TH
1.7 mA 3
T
A
= -40
o
C to 25
o
C ∆I
TH
2.5 mA 3
Temperature at minimum threshold
current
T
O
-20 50
o
C 3
Slope Efficiency T
A
= 25
o
C η 0.225 0.4 0.6 mW/mA 4
T
A
= -40
o
C η 0.75 mW/mA
T
A
= 85
o
C η 0.19 mW/mA
Slope Efficiency Temperature
variation
T
A
= 0
o
C to 70
o
C ∆η/∆T -6000 ppm/
o
C 5
Peak Wavelength I
F
= 7mA,
T
A
= 0
o
C to 85
o
C
λ
P
830 850 860 nm
λ
P
Temperature Variation I
F
= 7mA,
T
A
= -40
o
C to 85
o
C
∆λ
P
/∆T 0.06 nm/
o
C
Spectral Bandwidth, RMS I
F
= 7mA ∆λ 0.65 nm
Laser Forward Voltage I
F
= 7mA V
F
1.8 2.0 V
Rollover P
max
1.25 mW 6
Rise and Fall Times Pavg = 2mW,
Extinction Ratio = 10
t
r
t
f
130
150
ps 7
Relative Intensity Noise 1 GHz BW, I
F
= 7mA RIN -130 -122 dB/Hz
Series Resistance I
F
= 7mA , T
A
= 25
o
C R
S
25 35 50 Ω
T
A
= -40
o
C R
S
60 Ω
T
A
= 85
o
C R
S
20 Ω
Series Resistance Temperature
Coefficient
I
F
= 7mA,
T
A
= 0
o
C to 70
o
C
∆R
s
/∆T -3000 ppm/
o
C 8
Beam Divergence θ 15 30 Degrees 9
Beam Divergence Current
Variation
∆θ/∆Ι
F
0.45 Degree/mA
Photodiode Parameters Test Condition Symbol Min. Typ. Max. Units Notes
Monitor Current Po = 2mW, T
A
= 25
o
C I
PD
TBD 0.025 TBD mA 10
Po = 2mW, T
A
= -40
o
C I
PD
TBD TBD 10
Po = 2mW, T
A
= +85
o
C I
PD
TBD TBD mA 10
Monitor current Temperature
Variation
Po = 2mW, 0
o
C to 70
o
C ∆I
PD
/∆T TBD %/
o
C 10
Monitor Current Tracking Deltrk TBD 10, 11
Dark Current Po = 0mW, V
R
= 3V I
D
20 nA
PD Capacitance V
R
= 0V, Freq = 1MHz
V
R
= 3V, Freq = 1MHz
C 75
40
100
55
pF
HFE4094-542 Product Specification – Aug 2014
F i n i s a r
Confidential and Proprietary © 2013 Finisar Corporation. All rights reserved Rev. A1 Page 4
1. Reliability is a function of temperature, see www.finisar.com for details.
2. For the purpose of these tests, I
F
is DC current.
3. Threshold current varies as (T
A
– T
O
)
2
. It may either increase or decrease with temperature,
depending upon relationship of T
A
to T
O
. The magnitude of the change is proportional to the
threshold at T
O
.
4. Slope efficiency is defined as ∆P
O
/∆I
F
.
5. To compute the value of Slope Efficiency at a temperature T, use the following equation:
η(T) ≈ η(25
o
C)*[1+(∆η/∆ T)*(T-25)]
6. Rollover is the power at which a further current increase does not result in a power increase.
7. Rise and fall times specifications are the 20% - 80%. Most of the devices will measure <135ps fall
time. Rise and fall times are sensitive to drive electronics.
8. To compute the value of Series Resistance at a temperature T, use the following equation:
R
S
(T) ≈ R
S
(25
o
C)*[1+(∆R
S
/ ∆T)*(T-25)]
9. Beam divergence is defined as the total included angle between the 1/e
2
intensity points.
10. These specifications are for the TO-46 component alone. Reflections introduced by any
subsequent higher level assembly may affect these values.
11. Monitor current tracking is defined as follows:
III. Typical Performance Curves
Emitted Power vs. Current: Power varies approximately
linearly with current above threshold.
Threshold Current vs. Temperature: Threshold
current varies parabolically with temperature; thus it can
be nearly constant for a limited temperature range.
T e m p e r a tu r e
Threshold Current
T
M IN
, I
M IN
I
T H
≈
≈ ≈
≈ I
M IN
[1 . 1 × 1 0
- 4
(T -T
M IN
)
2
+ 1 ]
0.45mW / 0.45mW) (PI
0.75mW / 0.75mW) (PI
Deltrk
OPD
OPD
=
=
=
Current
Pmax
Typical operating current / power
I
th
η
HFE4094-542 Product Specification – Aug 2014
F i n i s a r
Confidential and Proprietary © 2013 Finisar Corporation. All rights reserved Rev. A1 Page 5
IV. Environmental Specifications
Parameter Symbol Min Typ Max Units Ref.
Case Operating Temperature T
op
-40 100 °C
Storage Temperature T
sto
-40 85 °C
V. Regulatory Compliance
Feature Agency Standard Certificate
Number
Laser Eye
Safety
FDA/CDRH CDRH 21 CFR 1040 and Laser Notice 50 9521487
Copies of the referenced certificates are available at Finisar Corporation upon request.
VI. Mechanical Specifications
(dimensions are in inches)
PIN Description
1 A
LD
2 K
LD
, A
PD
3 K
PD
HFE4094-542 Product Specification – Aug 2014
F i n i s a r
Confidential and Proprietary © 2013 Finisar Corporation. All rights reserved Rev. A1 Page 6
VII. Revision History
Revision Date Description
B00 8/14/2014 • Changed to Latest Finisar format.
VIII. For More Information
Finisar Corporation
1389 Moffett Park Drive
Sunnyvale, CA 94089-1133
Tel. 1-408-548-1000
Fax 1-408-541-6138
sales@finisar.com
www.finisar.com
