OsTech Laser Lab Source LDX Series User manual

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Laser Lab Source
a division of Research Lab Source Corporation
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phone: [phone]
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PRODUCT MANUAL
LDX-976nm-45W

Overview
The LDX-Series Laser Diode Sources are high quality fiber-coupled laser diode
sources based on a robust and reliable laser diode and temperature controller
architecture, with a focus on precision, reliability, and laser safety. All LDX systems
include the controller, temperature controlled mount, and a carefully selected fiber-
coupled laser diode from a top global manufacturer.
Before the system is shipped, the laser diode is integrated into the system, the
safe-oprating limits are programmed, and the entire system is tested and calibrated.
Different system forms are available:
vBenchtop discrete systems based on individual controller and mounting units,
featuring front-panel and remote control ability (RS232 / optional USB)
vCompact OEM solutions, with RS232 interface and no front panel
vRack-mounted systems with a fully enclosed fiber-coupled laser diode
module, front panel control, and RS232 interface
All devices have an integrated QCW pulse generator and can be run from QCW
pulsed to CW mode. External digital and analog modulation functionality is also
included on all models. The standard RS232 interface can be used for
configuration, operation and moni toring. A USB interface is optionally available on
all models. Every unit passes a burn-in inspection, a full functional test and a final
calibration prior to shipment.
General Features
•ull digital control, standard interface RS232 or USB
•on volatile pre-configuration EEPROM
•Controllable internal and external fan supplies
•ardware interloc
•Over-temperature and over-current protection
•Precise current controlled CW and pulsed laser operation modes
•Low power dissipation by active voltage control in CW mode
•Multiple laser diode safety features
•nternal and external modulation functions
3

TEC Controller Features
•Thermosensor input for TCs standard 10 , PT100, PT1000 or others
•Polynomial and Steinhart-art sensor model
•PD temperature controller for TEC coolers
•Voltage, current and temperature limits
•Target temperature seuencer on reuest
4

3
5
7
Contents
Overview
Contents
1 Introduction
2 Technical parameters 8
2.1 General parameters .............................. 8
2.2 Laser module ................................. 8
2.2.1 Security breakdown conditions ................... 9
2.3 Peltier module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3 Keypad and display menus 11
3.1 Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.2 Display Menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.2.1 Main Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.2.2 Laser Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.2.3 TEC Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.2.4 Device Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
16
4 Hardware setup preparations
5 Laser control 17
5.1 Preparations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.2 CW mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5.2.1 Switching on the laser . . . . . . . . . . . . . . . . . . . . . . 17
5.2.2 Ramp on laser switching . . . . . . . . . . . . . . . . . . . . . .18
5.2.3 Power control mode . . . . . . . . . . . . . . . . . . . . . . . 18
5.3 Gate option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
5.4 Modulation modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.4.1 Internal digital modulation mode . . . . . . . . . . . . . . . . 20
5.4.2 External digital modulation . . . . . . . . . . . . . . . . . . . . 21
5

Contents
5.4.3 External analog modulation . . . . . . . . . . . . . . . . . . . 21
5.5 Pilot laser control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
6 Temperature controller and sensors 23
6.1 PID controller parameters . . . . . . . . . . . . . . . . . . . . . . . . 23
6.2 Temperature sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7 Remote control 27
7.1 Standard mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
7.2 Reduced mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
7.3 Binary mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
7.4 Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
8 Error codes 29
9 Command reference 30
9.1 Laser commands (L) . . . . . . . . . . . . . . . . . . . . . . . . . . 30
9.1.1 Laser current commands (LC) . . . . . . . . . . . . . . . . . . . 30
9.1.2 Laser voltage commands (LV) . . . . . . . . . . . . . . . . . . 30
9.1.3 Laser photo current (LPC) and power (LP) commands . . . . . 30
9.1.4 Laser modulation commands (LM) . . . . . . . . . . . . . . . 31
9.1.5 Laser sequencer commands (LZ) . . . . . . . . . . . . . . . . 31
9.1.6 Pilot laser commands (P) . . . . . . . . . . . . . . . . . . . . 31
9.2 Temperature sensor and TEC commands (xT) . . . . . . . . . . . . 31
9.2.1 Temperature sensor commands . . . . . . . . . . . . . . . . . 32
9.2.2 TEC commands . . . . . . . . . . . . . . . . . . . . . . . . . . 32
9.3 General commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
9.3.1 Status command . . . . . . . . . . . . . . . . . . . . . . . . . 33
9.3.2 Mode commands . . . . . . . . . . . . . . . . . . . . . . . . . 33
6

 ntrutin
The LDC series precision laser diode drivers offer the user full control of all
configuration parameters through a front panel andor through a serial interface.
t is
important to read this manual thoroughly before turning on the
device for the first
time. The operating instructions should be followed for safe operation and optimum
performance of the laser diode.
n ae  uetin r prle pleae ntat aer a
ure in rt eria r ur erie ta at Oe in
urpe
  L L   LD
contactlaserlabsource.com 800-8-0
I OsTech, Berlin ermany
Tel. 4 30 23040 contactostech.de
Please note that unauthorized opening of the device cancels the two year
warranty. Don’t break the calibration seal!
7

2. Technical Parameters
    LL DL
input voltage DS01: 24 V DC ±10%
DS11: 110–220 VAC
ambient temperature 0...40 C
humidity <95%
housing size width◊height◊depth (depth without connectors)
o44 housing 105 mm ⇥44 mm ⇥160 mm
(4.1 in ⇥1.7 in ⇥6.3 in)
o85 housing 105 mm ⇥85 mm ⇥160 mm
(4.1 in ⇥3.3 in ⇥6.3 in)
t85 housing 105 mm ⇥85 mm ⇥200 mm
(4.1 in ⇥3.3 in ⇥7.9 in)
t95 housing 119 mm ⇥95 mm ⇥235 mm
(4.7 in ⇥3.7 in ⇥9.3 in)
t127 housing 200 mm ⇥127 mm ⇥277 mm
(7.9 in ⇥5.0 in ⇥10.9 in)
t192 housing
(19 inch, 2 HU)
483 mm ⇥89 mm ⇥266 mm
(19 in ⇥3.5 in ⇥10.5 in)
t193 housing
(19 inch, 3 HU)
483 mm ⇥133 mm ⇥266 mm
(19 in ⇥5.25 in ⇥10.5 in)
remote control PC serial interface RS232
   L D   
laser diode current range 1.5 |2.5 |5|8|12 |16 |24 |32 |40 ...100 A
resolution Imax/4000
accuracy ±0.5 %
laser current limit range 0...Imax
resolution Imax /4000
8

accuracy ±2%
laser diode voltage min. 1.2 V
max. 3|6|9|12 |15 |18 |24 |48 V
current noise 1%...0.01 % of Imax rms
internal pulse mode
pulse width range NPEFMTQFDJGJDµs...232µs(71min)
pulse period range (pulse width +100 µs)...232 µs (71 min)
time base accuracy ±1%
pulse to pulse accuracy 30 µs
rise time at 2.5 A
Imax
<2µs
at 4 A Imax <3µs
at 8 A Imax <10 µs
at 12 A Imax <15 µs
at 16 A Imax <18 µs
>16 A Imax 25–40 µs
on request <1µs...3µs
fall time 70 % ...100 % of Trise
laser fan control
voltage range 1.2 V ...24 V (adjustable by software)
current max. 300 mA
2.2.1 Security Shut-Down Conditions
•nterloc open
•nternal supply failure
•Abnormal transients
•Open circuit  no laser connected
•nternal overtemperature
•Beyond max. power dissipation
9

 Model Specific TEC Controller
peltier current range ±1.5 |±2.5 |±4|±8|±10 |±12 |±16 A
accuracy ±Imax/4000
peltier voltage max. 4|8|14 |18 |24 |48 V
temperature controller range ≠25 C...150 C, larger on request
accuracy typical: <10 mK
max.: <100 mK
temperature limits range ≠25 C...150 C
default lower limit 5C
default upper limit 35 C
10

3. Keypad and Display Menus
For OEM-Type Models, this section does not apply.
 
UP •increases the digit under the cursor
DOWN •decreases the digit under the cursor
LEFT •moves to the previous input field, unsaved changes are discarded
RIGHT •moves to the next input field, unsaved changes are discarded
OK or Enter •triggers actions
•toggles checkboxes
•saves a changed value
•
moves the cursor position if pressed on an unchanged or already
saved value
 D 
After power-on, the main menu is shown on the display. Some fields can be used
to
change settings of the device, others only show the current values. ou can
switch to the next menu with the arrow in the upper right corner. The laser menu
is next.
Then follow the TEC menus. The last menu is the device menu for general
settings.
  
The main menu gives an overview over the current state and allows you to
control
basic settings. The layout of the main menu depends on the model. t is
shown in figure 3 .1. The large number show the present laser current in
laser
drivers and the current temperature in TEC controllers. The following fields
may be
available in the main menu:
11

Laser On switch the laser on and off, can only be changed if the device has
no separate laser switch
LCT laser current target
LVA laser voltage actual
LCB laser current bias (for modulation)
CW Mode, ... Mod. modulation mode
TEC On switch the TEC controller on and off
TT, LTT, CTT target temperature
TA, LTA, CTA temperature actual
TCA, LTCA, CTCA TEC current actual
TVA TEC voltage actual
TCL TEC current limit
Error# error number (0 = no error)
Interlock if the interlock is closed
(a) Laser driver without
TEC controller.
(b) Laser driver with
one TEC controller.
(c) Laser driver with
two TEC controllers.
(d) Controller for one TEC. (e) Controller for two TECs.
Figure3.1:Mainmenulayoutdependingonthemodulesinthedevice
 L 
The laser menu is shown in figure 3.2. This is where the user can
change laser current settings. The following fields are included:
12

LCL laser current limit
LVC compliance voltage (LVA)
LVA laser voltage actual
LCB laser current bias (for modulation)
LCLM limit for average laser current (for modulation)
LTM laser temperature maximum, laser stops above this temperature
Error# error number (0 = no error)
CW Mode no modulation
LMAX external analog modulation
LMDX external digital modulation
LMDI internal digital modulation
LMW laser modulation width
LMP laser modulation period
PC pulse count (= LMDIC command)
•PC =1: single pulse
•PC =2: burst of 2 pulses . . .
•PC =0: continuous pulses
LG gate option
Figure3.2:Lasermenu
3.2.3 TEC Menu
The TEC menu is shown in figure 3.3a. This is where the user can change TEC
controller settings. The following fields are included:
TEC Contr. On switch the TEC controller on and off
TT target temperature
TA temperature actual
TCL TEC current limit
TCA TEC current actual
13

TVA TEC voltage actual
TC Auto On TEC controller is automatically activated when the temperature is
whithin limits
Restore Def. restores the default settings for the TEC controller
TLU upper temperature limit
TLL lower temperature limit
PID parameters set the PID coefficents (see figure 3.3b)
Select Sensor select one of some predefined temperature sensor settings (see
figure 3.3c)
Sensor Param. manually set the temperature sensor settings (see figure 3.3d)
(a) TEC menu. (b) Dialog: PID Parameters.
(c) Dialog: Select Sensor. (d) Dialog: Sensor Parameters.
Figure3.3:TECMenuanddialogsinit.
3.2.4 Device Menu
The device menu is shown in figure 3.4. This is where the user can change
general settings and find out the type and serial number of your device. ou find
the following fields in this menu:
External Control on
Start
Switch to external control automatically after power-on. You get
the chance to abort this.
Switch to External
Control
You can control the device over the RS232 interface after activating
this.
Pilot laser Switch the pilot laser on and off.
Intensity pilot laser intensity (0. . . 16)
14

GFD default fan voltage
Restore Default Settings Reset all settings in the device to their default values.
Service Show type, serial number and software version of the device.
Figure 3.4: Device menu.
15

4. Hardware Set-Up Preparation
Thesestepsmustbefollowed:
•MakesurethatthepowersupplyisdisconnectedfromZPVSmainQPXFSTVQQMZ.
•
UseanapprovedpersonalgroundingbraceletorothermeansforESDprotection
duringtheassemblyofthelaserorotherelectronics.
•Connectyourlasertotheproperconnectorsofthedriverunit.
•
RemovetheshortJOHclipfromthelaser. Whileturnedoffthelaseroutputof
thedriverunitisinternalMyshorteE.
•Connectthepowersupplyunittothepropersupplyvoltage.
•Makesurethattheinterlockconnectorisclosed.
•
Makesurethattheemergencybutton(thelargeredbuttonPOthefront)is
unboltedQVMMFEPVU.
•
Makesurethatanappropriatetemperaturesensorforthelaserisconnected.
ThelaserdriverneedsatemperaturesignalUPBDUJWFUIFESJWFDVSSFOU.
•Pleasenotelasersafetyregulations!
•Turnthekeyswitchon.
16

5. Laser Diode Current
 
FirstthelasercurrentlimitandthelasercompliancevoltageNVTUbeconfigured.
To
adjustthelasercurrentlimitusingthedisplay:
•go to the Laser Menu by pressing and
•go to the LCL input field by pressing to adjust the laser current limit
•to move the cursor position press several times
•to increase/decrease the digit press / as often as necessary
•after adjusting the value press to enter the new value
After the step above, the user should adust the laser compliance voltage  LVC
input field to an expected voltage drop slightly above the laser's rating.
These values can also be set by using the RS232 interface see chapter . To do
this use the commands LCL and LVC.
5.2 CW Mode
The mode of operation can be selected in the laser menu. The CW mode is
active by default
when all of the modulation modes LMD, LMD and LMA are
uncheced.
.2.1 Switching on the Laser Diode
o to the main menu and adust the laser current target in the LCT input
field. The selected value must be under the laser current limit and the maximum
operating current of your laser module. Enable the LOO input field to
switch on current to the laser. The LED on the front panel will start blining
and the actual current will be displayed. Disabling it switches off the laser and
causes the red LED on the front panel to stop blining. The actual current 0.00
A will be displayed. Pressing the emergency button on the front panel interrupts
the power supply immediately. Unbolt it by twisting.
17

0t
ILaser
LCTmax
LCT
LZTR LZTR
LZTR:0...34000ms
(default: 300 ms)
Figure 5.1: Laser current on-off ramp in CW mode. The ramp is active at any change
of laser current.
WhenusingtheRS232interfacethecommandLRmaybeusedtoswitchthelaser
on. ThecommandLSswitchesthelaseroff.
5.2.2 Current Ramp to Laser Current
InCWmodetheramponlaserrunandstopisactivatedbydefault. However,
this functionisnotavailableoverthedisplaymenus. 5PVTFUIJTGFBUVSFyouneedto
controlthe driveroveranRS232interface. Withe.g. LZTR2000 youcansetthe
timetoreachthe maximumcurrentTFUQPJOU GPS ZPV MBTFS EJPEF Theslopeofthe
rampwJMMbe LCTmax/2000ms inthisexample. Duringthelaserstopramp,you
canturnoffthelaserimmediately bysending LSDPNNBOE again. Youcandisable
therampwith LZTR0 . Thedefaultvaluefor LZTR is 300ms . Figure5.1shows
how LZTR works. Foralistofothercommandssee chapter9.
5.2.3 Laser APC Power Control Mode
ThepowercontrolmodeisonlyavailableinCWmodeandconsistsoftwo
indepen dentparts:
•Thephotocurrentcontrolloop
• Thelaserpowercoefficientswhichdoatranslationfromapowervalueinto
a valueforthephotocurrent
Toinitiatethe"1$powercontrolyoumustfirstpreparethelaserforproperoperation
 inCWmode(seesection5.1). Don’tforgettoadjustthelasercurrentlimit.
18

5.3Gateoption
Before turning the laser EJPEF on you must connect the photosensor between
the PDC(cathode) and the GND (anode) pins at the laser connector. After this
you should test whether the sensor JT XPSLJOH. For this TUFQ run the laser and
check with the LPCA command (laser photocurrent actual). The default
maximum photo currentis700µA,butcanbeincreasedonrequest. Enter your
target photo current with the LPCT command. Initiali[e the photo current
control mode by the command LPCCR (laser photo current control run). Now you
canrunandstopthelaserby LR and LS .Assoonasyoustartthelaserthedriver begin
scontinuously to track and control the photo current. The second step is to
adjust the power coefficients so that you can use power valuesinWattT.
ForthisEPBTGPMMPXT
• adjustUIF LPT value(laserpowertarget),itshouldhaveatypicalora
maximum value
• SunthelaserinnormalCWmodeandsFUthecurrentUPtheQPJOUUIBUUIF
laseremitsexactthetargetlaserpower. Anexternalpowermeteris
necessaryfor this. Nowexecutethe LPF commandtofixtheactualphoto
currentvaluetothis laserpower.
You can now can get the laser power by thecommand LPA , set the power
target by the LPT command, run the power control mode by the
LPCCR command. Start andstop thelaserbyLRandLS.
5.3 Gate Option
There is a gate option which can be used in CW mode as well as in internal
digital modulation mode. ou may switch on and off the internally generated laser
current by the modulation input. Optionally, a separate gate pin may be used.
n this case the gate option is also available in the external modulation modes.
The gate option is activated by the command LR and deactivated by LS .
Additionally, the LMDR command can be used to negate the modulation input.
5.4 Modulation Modes
The modulation modes can be selected in the laser menu. Changing modulation
modesturnsoffthelaser. Youmaystartthelaseragainthemainmenu.
Pleasenotethatthepreparations—asdescribedinsection5 .1—havetobedone
first.I nmodulationmodesthemeasuredcurrentsandv oltagesdisplayedinthemain
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t
Ilaser
0
laser bias current – LCB
laser current target – LCT
LMW
LMW:100...2
32 µs
LMP:200...2
32 µs
LMP LMW +100 µs
LMP
Figure 5.2: continuous pulse mode
menu show the mean values not the peak values. These measured values may
differ from the adjusted ones caused by the low speed of the AD converter.
Don’t care about this. The real values are within the limits as described above.
5.4.1 Internal Digital Modulation Mode
The driver is able to modulate the laser current by internally generated pulses. This
internal modulation mode may be activated by checking the LMDI input field in the
laser menu or entering the LMDIR command.
Continuous pulse mode
Unless configured otherwise, pulses are generated continuously as you can see in
figure 5.2. You have to enter the pulse width (duration) and pulse period in µ s. Take
care of the right proportions of these values. The pulse width is in the range of
100 µs . . . 4 × 109 µs and may be changed by the LMW command. The pulse
period ( LMP command) is in the range of (LMW + 100 µs) ... 4 × 109 µs , so it is
always at least 100 µs larger than the pulse width.
Newer devices are not subject to these limitations. Here, LMW and LMP can be
set freely in steps of 1 µs.
You can run and stop the laser by the commands LR and LS.
Single pulse mode, n-pulses mode
This mode—which is illustrated in figure 5.3—is useful if you want to generate only a
single pulse or a certain number of pulses. To activate it first select the internal
digital modulation mode as stated above. Then enter the command LMDIC n where n
is the number of pulses you want to be generated. After entering the LR command
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t
LMDIC =2
LMW and LMP as in continuous pulse mode
LMDIC:0...64000
LMDIC =0continuous pulse mode
LMDIC =1single pulse mode
LMDIC =2...64000 n-pulsesmode
Figure5.3:singlepulsemode,n-pulsesmode
thenumberofpulseswillbegenerated. Afterwards,thedriverenterstheOFFstate
automatically. Youdon’tneedtoenterLS.
Assigning0toLMDICswitchestothecontinuouspulsemodedescribedabove.
External trigger mode
Toswitchtothismodeactivatethegateo ptioninsinglepulsemode/n-pulsesmode.
Thegate option( seesection5 .3)h asadifferentmeaninginthismode.
Activatingitenablesy outotriggerthebeginningo fthegeneratedpulsesexternally.
If L GR is activatedand L R wasenteredthedrivergeneratesthedefinednumbero fpuls
esas soonasalow-hightransitionatthemodulationinputoccurs.
5.4.2 External Digital Modulation
Theexternaldigitalmodulationmodemaybeactivatedbyenteringthe LMDX com-
mand. Ifthismodeisactiveandthelaserisrun( LR )thenthelaserisactivatedby
a TTL high-level at the modulation input and vice versa. The command
LMDXNR negatesthislogicsothatthelaserwillbeactivatedbyTTLlow-level.
Thismodeis similartotheCWmodewiththegateoptionactivated.
However,inthismodeyou cansetalaserbiascurrent(LCB).
5.4.3 External Analog Modulation
Theexternalanalogmodulationmodeisselectedbyenteringthe LMAX command.
InthismodethelasercurrentcanbecontrolledbythevoltageattheAMODinput
where 4V correspondsto Imax . Thecompliancevoltage( LVC )hastobesetbefore
andthelaserhastoberunbyLR.
Theinputhasaninternalterminatingresistorof 10kW . Ifyouwanttoconnecte.g.
a10Vsignal,youshouldusea15kWresistorinseriesexternally.
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