DS‐7046 REV04
Apr 2014

EM650 High Power DFB Laser Module
General Description
The EM650 integrates a high‐power fiber‐coupled DFBlaser with both an ultra‐low noise laser current source
and temperature controller. It represents a precision
OEM solution for fiber coupled high power DFB lasers
operating with excellent frequency stability, narrow
linewidth, low noise, and stable polarization. The
module contains a high‐power DFB laser, optical isola‐tor, single‐mode fiber pigtail, thermo‐electric cooler,
thermistor, and monitor detector integrated with alaser current source, temperature controller, andmonitor detector readout amplifier. The entire module
operates from a single +5 V supply. The unit provides abi‐directional power adjust input that may be used for
SBS prevention, for constant power operation in con‐junction with the monitor detector readout signal andan external control loop, or for finely adjusting thelaser oscillation frequency via chirp. The unit also incorporates a bi‐directional temperature adjust input forcoarse tuning of the laser oscillation frequency. The module is designed and built using Gooch & Housego’s high‐reliability platform for defense components and incorporates an advanced ultra‐low noise laser current source.
The EM650 drives the internal TEC with a class AB linear H‐bridge and incorporates multiple layers of EMI pro‐tection. It is G&H’s highest performance integrated laser solution and offers performance comparable to labor‐
atory equipment in a much smaller package.

Applications






Long haul WDM transmission
RF Links
CATVSeedingSensing
Low‐noise High‐power Source

Basic Operating CircuitFeatures








Integrated current source
Integrated temperature controller
Integrated monitor detector amplifier
High optical output power
ITU Wavelengths – Full C band coverage
Low RIN
Narrow Linewidth
PM/SM fiber with or without furcation tubingSimple Interface
Small form factor
Operates from single +5V supply

Ordering Information
The EM650 part number has the following structure:
EM650‐FFFFFF‐POW‐FIBUM‐CON‐NA
Valid values for each field are included at the end of
this document.
G&H Boston +1 781 275 7501
bostonsales@goochandhousego.com

www.goochandhouego.com

G&H Europe +44 115 714 1064
europe@goochandhousego.com
Page 1 of 12

DS‐7046 REV04
Apr 2014

EM650 High Power DFB Laser Module
Absolute Maximum Ratings
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings
only and operation of the device at these or conditions beyond these is not implied. Exposure to absolute maximum ratings for extended
periods of time may affect device reliability.

ParameterSym.

ConditionMinMax

Unit

Storage Temperature

TSTG

non‐condensing atmosphere‐40+85C

Operating Temperature

TOPtemp. at base of module,
non‐condensing atmosphere‐1565CVoltage Supply

VCC

4.75.5

VCurrent Supply

ICC3.5A

Laser Enable Input Voltage

LEVCC +0.3

V

Laser Enable Input Current

ILE2mA

Power Adjust Input Voltage

Vpa

Power Adjust
Source or Sink

Input

Current

Temperature Adjust Input Voltage

Vta

Temperature Adjust Input Current
Source or Sink
Monitor Detector Output Voltage

VMON

Monitor Detector Output Current
Source or Sink

IMONOptical Output PowerPopG&H Boston +1 781 275 7501
bostonsales@goochandhousego.com

GND‐0.3

Warning: see notes

02.6

VWarning: see notes‐3.53.5mA

Warning: see notes

05V

Warning: see notes‐3.53.5mA

VCC

V15mA

110mW

‐15

www.goochandhouego.com

G&H Europe +44 115 714 1064
europe@goochandhousego.com
Page 2 of 12

DS‐7046 REV04
Apr 2014

EM650 High Power DFB Laser Module
Optical Characteristics
TOP=25C unless otherwise noted, All parameters measured after an initial 60s settling time. VCC = LE = 5.0V with
PA and TA open.
Parameter

Sym.

Optical Output Power Setpoint

POP

Optical Output Power Fluctuation1

POP

Long‐Term Power Fluctuation

POP1σ, tm=20hr,0.1s avg, 18s period

Temperature Dependent PowerDriftPT‐10 ≤ TOP ≤ 60

Optical Frequency Accuracy2FOP

Optical Frequency Stability3

FOPSee note 3

FT‐10 ≤ TOP ≤ 60

Temperature
quency Drift

Dependent

Fre‐Side Mode Suppression Ratio

Condition
See ordering in‐formation
1σ, tm=400s,0.1s avg&period

Optical Isolation


Relative Intensity Noise4

RIN

Cold Start Settling TimeMax

PopUnitmW

2050

PPM

200500

PPM500

PPM/°C+5GHz<20MHz±20030w/ PM fiber only

LinewidthTyp‐5SMSR

Polarization Extinction Ratio

MinMHz/°CdB

1720dB

3035dB170

kHz

50 MHz to 18GHz‐155

VCC=VEN 05V

‐150dBc/Hz30s

Rise Time (Hot Start)

tR

VEN=05V

30ms

Fall Time (Hot Standby)tF

VEN=50V

5µs

Back Facet Tracking Over Temp

G&H Boston +1 781 275 7501
bostonsales@goochandhousego.com‐10

www.goochandhouego.com+10%

G&H Europe +44 115 714 1064
europe@goochandhousego.com
Page 3 of 12

DS‐7046 REV04
Apr 2014

EM650 High Power DFB Laser Module
Electrical Characteristics
Parameter

Sym.

Condition

Voltage Supply

Vcc

across inputs

Current Supply

Icc

Laser Enable HighLEH

Laser Enable Low

LEL

Laser Enable Input Impedance

ZLE

Power Adjust4Vpa

Warning: see notes

Power Adjust Input Impedance

ZPA

to 2V Vref

1k

‐3dB8kHzPower Adjust BandwidthMin

TypMax

5V
33.5

5

Vta

Warning: see notes

Temp Adjust Input ImpedanceZta

to 2.5V Vref

Monitor Detector Output

VMON

at PopAV

1.5Temperature Adjust

Unit0k
2.2

1.5

3.5
11VVVk

3VMax

Unit

Environmental Characteristics
ParameterSym.

Condition

Min

Storage Temperature

Tstg

non‐condensing‐40+85°C

Operational Temperature

Toptemp. at base of module,
non‐condensing‐10+60°C

G&H Boston +1 781 275 7501
bostonsales@goochandhousego.com

www.goochandhouego.com

TypG&H Europe +44 115 714 1064
europe@goochandhousego.com
Page 4 of 12

DS‐7046 REV04
Apr 2014

EM650 High Power DFB Laser Module
Electrical Connector
PinNameDescription

1

VCC

Voltage supply

2VCC

Voltage supply

3

GND

Ground connection

4

GND

Ground connection

5

GND

Ground connection

6TA

Temperature Adjust Input

7VmonMonitor Voltage Output

8LELaser Enable

9PA

Power Adjust Input

ShieldConnected to connector shield only

MatingConnector

DB‐09F, Standard DB‐09 Female/Receptacle/Socket Connector

G&H Boston +1 781 275 7501
bostonsales@goochandhousego.com

www.goochandhouego.com

G&H Europe +44 115 714 1064
europe@goochandhousego.com
Page 5 of 12

DS‐7046 REV04
Apr 2014

EM650 High Power DFB Laser Module
Optical Fiber Specification
Parameter

TypeUnit

Fiber Type

Single‐mode PM or non‐PM‐Core Diameter

8µm

Outer Diameter

125µm

Buffer Diameter

250 (optional 900 μm loose buffer avail.)µm

Buffer Material

Acrylate (optional loose‐buffer is PVDF)‐Minimum Length

1mMinimum Bend Radius

35mm

Connector TypeFC or SC/APC, key parallel toslow axis; key type is tight‐fit/narrow‐

Output Polarization

Parallel to slow axis

‐Mechanical Drawing

Φ[.125]
3.17[inches]mm

G&H Boston +1 781 275 7501
bostonsales@goochandhousego.com

www.goochandhouego.com

G&H Europe +44 115 714 1064
europe@goochandhousego.com
Page 6 of 12

DS‐7046 REV04
Apr 2014

EM650 High Power DFB Laser Module
Typical Operating Characteristics (80 mW Module)

Pop vs Top

Icc vs Top
7.5

2

Frequency Deviation (GHz)

Drive Current (A)

85Power (mW)

Frequency vs Top
10.0

2.590

1.58075

10.5070‐100102030405060‐100102030405060

5.0
2.50.0‐2.5 ‐100102030405060‐5.0‐7.5‐10.0

Tracking Error vs Top
15%
10%
5%0%
‐100102030405060

‐5%
‐10%
‐15%

G&H Boston +1 781 275 7501
bostonsales@goochandhousego.com

www.goochandhouego.com

G&H Europe +44 115 714 1064
europe@goochandhousego.com
Page 7 of 12

DS‐7046 REV04
Apr 2014

EM650 High Power DFB Laser Module
Typical Operating Characteristics (continued)

2Pout vs Vpa

461009080706050403020100Power (mW)

Frequency Deviation (GHz)

Freq Tuning vs Vta
50403020100‐10 0‐20‐30‐40‐500Vta (V)

0.5

11.5
Vpa (V)

22.5

11341Power stability of this magnitude is strongly influenced by any movement of the fiber. To duplicate this stability measure‐ment the fiber must be secured and motionless.
2For 228.849 THz (1310 nm) lasers the laser frequency tolerance is ±1.750 THz (±10 nm).
3Frequency stability measured by heterodyne of two free running EM650 units over 100s.
4
The peak of the RIN curve corresponds to the relaxation oscillation frequency of the laser which varies in proportion to thedrive 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 power using the PA input will reduce performance.

G&H Boston +1 781 275 7501
bostonsales@goochandhousego.com

www.goochandhouego.com

G&H Europe +44 115 714 1064
europe@goochandhousego.com
Page 8 of 12

DS‐7046 REV04
Apr 2014

EM650 High Power DFB Laser ModuleNOTESWARNINGS: several of the parameters listed inthe specifications above are denoted with awarning. These warnings are covered by the fol‐lowing notes which should be understood be‐fore operating the device.

Mounting
The EM650 is conductively cooled through its base andneeds to be mounted using a thermal interface mate‐rial to a customer supplied heatsink. Gooch & Housego
recommends Panasonic PGS series pyrolitic graphite
sheets, available in the US from Digi‐Key Corporation.
Care should be taken to keep the base temperature ofthe module between ‐10 and 60C at all times during
operation.

Noise suppression
The EM650 is a no‐compromises low‐noise integrated
laser solution; the temperature controller output isclass AB linear, there are no DC/DC converters in themodule, the lowest noise components and architec‐tures available are used along with heavy filtering and
EMI shielding. Nevertheless, power supply ripple andnoise should be minimized and the cable shield should
be connected to the EM650 connector shield and tied
to the appropriate signal at the power supply end of
the cable.

mance. However, some applications require fine tun‐ing of the laser bias current. The PA input provides thisfunctionality, but its use carries an amount of risk. Ifbias adjustment is not required this input should beleft open. Use of this input carries the potential to
overdrive the laser and/or circuitry with the ability todestroy or drastically reduce the device lifetime. No
internal protections on this input are provided, but theuser is encouraged to clamp or otherwise limit thevoltage and current that may be applied to this input.
The default operating power corresponds to an inputof 2.05V. For maximum reliability it is recommended
that power only be reduced, although if required it canbe driven as high as 2.2V (corresponding to a 10%
boost in output power). The safest method of using
this input is to pull the voltage down using an external
resistor or potentiometer to ground. Applying a re‐sistance to ground will create a voltage divide circuit
between the external resistance and an internal re‐sistance of 1K to the 2.05V reference. Damage due tooverdrive will not be covered under warranty. Use ofthis input will likely decrease the performance of theEM650 by bypassing its internal ultra‐low noise voltage
reference.
The PA input must never be shorted directly to Vcc
which would cause circuit malfunction or rapidly de‐stroy the DFB laser.

Temperature Adjust (TA)The EM650 is designed to operate the laser chip at aconstant temperature holding the output frequency
within 5 GHz of the ordered frequency. However, somePower Adjust (PA)applications require coarse tuning of the output fre‐
The EM650 is designed to run in constant current quency via temperature. In these cases, the laser may
mode with the drive current set for the as‐ordered
be tuned using the TA input. Temperature deviations
output power to achieve the highest possible perfor‐of more than a few degrees (50 GHz in laser frequency)
G&H Boston +1 781 275 7501
bostonsales@goochandhousego.com

www.goochandhouego.com

G&H Europe +44 115 714 1064
europe@goochandhousego.com
Page 9 of 12

DS‐7046 REV04
Apr 2014

EM650 High Power DFB Laser Modulefrom the as‐ordered setpoint may result in decreased
stability and increases the likelihood of the laser expe‐
riencing a longitudinal mode‐hop. The achievable tun‐
ing range will depend on the specific laser chip, theambient temperature, and the thermal resistance tothe ambient. Use of this input carries the inherent po‐
tential of overdriving the TEC. The TA input is clamped
to Vcc through integrated protection diodes. If Vta isestablished before Vcc these clamp diodes will con‐duct. The input current should always be limited to≤3.5mA to prevent destruction of the clamp diodes.
The safest method of driving this input is with a tri‐state output whose output is current limited when ac‐tive, maintained at high‐impedance until Vcc is estab‐lished, and whose output returns to high‐impedance
before Vcc is removed. The device warranty will not behonored for lasers with overdriven TECs. Use of this
input also carries the likelihood of decreased frequen‐cy stability as it bypasses the internal ultra‐low noisevoltage reference.

to deliver the maximum specified current at no lessthan the minimum voltage is therefore needed. Cur‐rent limiting below the specified maximum during thestartup phase will result in an internally measured
drive voltage lower than specified. This condition canresult in permanent, non‐warrantable damage to thedevice.
If the user fails to sequence the supplies as describedin the Power and Temperature adjust sections of thisdocument and Applications Note DS‐7047, the device
will immediately suffer non‐warrantable damage ordestruction.

Applications Information

Be sure to check the Gooch & Housego website for thelatest applications information for this device. Applica‐tion note DS‐7047 covers general usage of the EM650
along with information particular to tuning via tem‐
perature or chirp. If you plan to tune this device, it ishighly recommended that you read this app note. AThe TA input must never be shorted directly to Vcc or series of short videos showing optical heterodyne
ground which would cause circuit malfunction or rap‐ measurements that illustrate laser line stability are
idly destroy the DFB laser.
also available on the website.

GroundingCare must be taken with grounding, cabling, and con‐nections due to the amount of current the module
consumes. Make sure that the voltage on pins PA/TA
reference ground as close to the EM650 as possible ifeither input is connected. DO NOT connect the cableshield to ground at both ends of the cable to avoid
producing a ground loop. DO NOT connect the EM650
housing to ground to avoid producing a ground loop.

Startup Considerations
The EM650 consumes a considerable amount of cur‐rent in the startup phase and when operating at tem‐
perature extremes. A voltage source plus cabling able
G&H Boston +1 781 275 7501
bostonsales@goochandhousego.com

www.goochandhouego.comG&H Europe +44 115 714 1064
europe@goochandhousego.com
Page 10 of 12

DS‐7046 REV04
Apr 2014

EM650 High Power DFB Laser Module

Ordering Information
EM650‐FFFFFF‐

POW‐ FIBuM‐

CON‐NA

Parameter

OptionConnector

FCA
SCA

FC/APC
SC/APC

Fiber

SM250
SM900
PM250
PM900

Single Mode Fiber, 250um Buffer
Single Mode Fiber, 900um Loose
BufferPM Fiber, 250um Buffer
PM Fiber, 900um Loose BufferPower

10/15*
40506380100

Available at 1310nm only (PM/SM)
40mW Output
50mW Output
63mW Output
80mW Output
100mW Output

Frequency

FFFFFF

Frequency in GHz**
14‐PIN DFB w/ Integrated Electron‐
ics
14‐PIN DFB w/ Integrated Electron‐
ics, No Internal Optical Isolator

ProductFamily*EM650
EM651

Description

1310 nm lasers with PM fiber outputs are only available in 10mW versions.

**Standard frequencies range from 192.100 THz to 196.000 THz in increments of 100 GHz, with other fre‐quencies available upon request. 1310nm devices are 228.849 THz with a 1.75 THz tolerance.

G&H Boston +1 781 275 7501
bostonsales@goochandhousego.com

www.goochandhouego.com

G&H Europe +44 115 714 1064
europe@goochandhousego.com
Page 11 of 12DS‐7046 REV04
Apr 2014

EM650 High Power DFB Laser Module

DO NOT connect the DB‐9 connector on theEM650 to any commercial laser controller.
Warning:
This device requires between 4.6V and 5.5V as measured from the Vcc to GND terminals. These voltages must
be maintained for currents ranging from 0‐3A necessitating the use of short wires and/or large AWG wire.
Failure to supply sufficient voltage at the device terminals may result in excess current draw and permanent,
non‐warrantable damage. If the device draws 3A for more than 3 seconds, turn off power and check for exces‐
sive wiring resistance or a baseplate temperature outside the operational range.

Warning:
The TA and PA inputs should be driven with a current limited source with sequencing of the signal and power
supply as described in the datasheet. Failure to follow these guidelines has the potential to cause non‐warrantable damage to the drive electronics and/or laser module. If the device is to be tuned using either the PAor TA input, it is highly recommended that the user read and understand the G&H application note “DS‐7047Frequency Tuning a DFB Laser,” available on the G&H website.

Warning:A thermal interface material is required between the EM650 and a customer supplied heatsink. G&H recom‐
mends the use of Panasonic PGS Series flexible graphite sheets available in the US from Digi‐Key Corporation.

G&H Boston +1 781 275 7501
bostonsales@goochandhousego.com

www.goochandhouego.com

G&H Europe +44 115 714 1064
europe@goochandhousego.com
Page 12 of 12