CWDM INTEGRATED RF TRANSMITTER
High Bandwidth Directly Modulated DFB Laser Module
EM657
The EM657 high bandwidth integrated module is a member of Gooch & Housego’s line of high performance single-frequency modules based on precision DFB laser technology.
The EM657 RF Transmitter integrates a high-bandwidth fiber-coupled DFB laser with both an ultra-low noise laser current source and temperature controller. The module also contains an optical isolator and back facet monitor detector readout amplifier.
The entire module operates from a single +5 V supply and offers a bi-directional bias adjust input that may be used to control the laser output power or finely adjust the laser oscillation frequency via chirp. The unit also incorporates a bi-directional temperature adjust input for coarse tuning of the laser oscillation frequency.
The module is designed and built using our high-reliability platform for defense components and incorporates an advanced ultra-low noise laser current source.
The EM657 drives the internal TEC with a class AB linear H-bridge and incorporates multiple layers of EMI protection. The device accepts a standard female DB9 connector for the application of power and low-frequency tuning signals while the RF input accepts a standard male 2.92 mm “K” connector. The output optical fiber is available with or without PVDF furcation tubing terminated with a variety of standard optical connectors.
Models available
• 1310 nm and C-band wavelength options
with 18mW and 10 mW output power respectively
Features
• Integrated current source
• Integrated temperature controller
• Integrated monitor detector amplifier
• SM or PM fiber with or without furcation tubing
• Simple interface
• Small form factor
• Operates from single +5V supply
Applications
• RF links
• CATV
• Seeding
• Sensing
Optical Characteristics
TOP=25°C, continuous wave, and beginning of life unless otherwise specified. All parameters measured after an initial 60s settling time. VCC = LE = 5.0V with Power Adjust and Temperature Adjust (VPA and VTA) pins open.
Parameter
Sym
Condition
Min
Typ
Max
Unit
Optical output power setpoint
POP
1310 nm devices
18
mW
C-band devices
10
mW
Center wavelength
λOP
1310 nm devices, 25°C
λOP-10
λOP
λOP+10
nm
C-band devices, 25°C
λOP-1
λOP
λOP+1
nm
Optical output power fluctuation1
∆POP
1σ, tm=400s,
0.1s avg and period
65
100
PPM
Long-term power fluctuation
∆POP
1σ, tm=20hr,
0.1s avg, 18s period
0.1
0.2
%
Temperature dependent power drift
∆PT
-10 ≤ TOP ≤ 60°C
0.35
%/°C
Temperature dependent frequency drift
∆FT
-10 ≤ TOP ≤ 60°C
±750
MHz/°C
Side mode suppression ratio
SMSR
30
dB
Polarization extinction ratio
with PM fiber only
17
20
dB
Optical isolation2
30
35
dB
Relative intensity noise
RIN
Pop, 0.2-3 GHz
-150
dBc/Hz
Linewidth
4
MHz
Cold start settling time
VCC = VEN 0→5V
10
s
Rise time (hot start)
tR
VEN = 0→5V
120
µs
Fall time (hot standby)
tF
VEN=5→0V
3.8
µs
Back facet tracking over temp
-10
+10
%
Modulation bandwidth
10
12
GHz
1 Power stability of this magnitude is strongly influenced by any movement of the fiber. To duplicate this stability measurement the fiber must be secured and motionless.
2 Units are available without isolator (product series EM658). Devices without optical isolators are subject to mode-hops and are susceptible to back reflections. The wavelength stability devices with no optical isolator cannot be guaranteed.
Electrical Characteristics and Fiber Information
Electrical Characteristics
Sym
Condition
Min
Typ
Max
Unit
Voltage supply
VCC
across inputs
5
V
Current supply
ICC
3.5
A
Laser enable high
LEH
2.9
V
Laser enable low
LEL
2.9
V
Laser enable input impedance
ZLE
5
MΩ
Bias level adjust3
VPA
warning: see app notes
0
2.2
V
Bias level adjust input impedance
ZPA
to 2V VREF
9.74
kΩ
Bias level adjust bandwidth
-3dB
400
kHz
Temperature adjust
VTA
warning: see app notes
1.55
3.45
V
Temp adjust input impedance
ZTA
to 2.5V VREF
1
kΩ
Monitor detector output
VMON
at POP
1
3
V
Bias tee inductance
53
nH
3 The peak of the RIN curve corresponds to the relaxation oscillation frequency of the laser which varies in proportion to the drive current above threshold by frelax α ((Ild/Ithreshold) - 1)1/2. Customers employing this device in RIN sensitive applications should therefore be aware that reducing the bias level using the power adjust input will reduce performance. Reducing the bias level reduces the device modulation bandwidth by the same relationship.
Fiber Characteristics
Fiber type
Single-mode, PM or non-PM
Core diameter
8 μm
Outer diameter
125 μm
Buffer diameter4
250 μm
Buffer material4
Acrylate
Minimum length
1 m
Minimum bend radius
35 mm
Output polarization
Parallel to slow axis
Connector5
FC/APC
4 Optional 900 μm loose-tube PVDF buffer recommended for laboratory use. 5 Other connector options available, contact sales for more information.
Drawings and Performance Graphs
Drawings and Performance Graphs, Continued
DFB Laser Modules, RF
EM657
1310 nm
18 mW
DFB
MODULE
SM/PM
12 GHz direct mod,RF Common Ground
DFB Laser Modules, RF
EM657
1527 thru 1565 nm
10 mW
DFB
MODULE
SM/PM
12 GHz direct mod,RF Common Ground
商品属性 [波长] 1310 nm [功率] 18 mW