robust stabilized co 2 lasers with line tracker
DESCRIPTION
Robust Stabilized CO 2 Lasers with Line Tracker. Access Laser Company where innovation never stops. Main Features. Offered with stabilized or grating tuned lasers Robust stabilization allows field applications where ambient environment changes. - PowerPoint PPT PresentationTRANSCRIPT
www.accesslaserco.com ♦ 5603 47th Ave NE, Marysville, WA 98270, USA ♦ 360-651-6141
Robust Stabilized CO2 Laserswith Line Tracker
Access Laser Companywhere innovation never stops
www.accesslaserco.com ♦ 5603 47th Ave NE, Marysville, WA 98270, USA ♦ 360-651-6141
Main Features• Offered with stabilized or grating tuned lasers• Robust stabilization allows field applications where
ambient environment changes.• Stabilization without the side-effect of “chirping” inherent
with the traditional dithering scheme. • Power, spectrum, longitudinal mode and transverse
modes are all stabilized at the same time.• Maintains the stability of laser at any power level that is
independently adjusted.• Optimized sampling scheme depends on specifics of the
laser model. Contact factory for details.
www.accesslaserco.com ♦ 5603 47th Ave NE, Marysville, WA 98270, USA ♦ 360-651-6141
The Idea: Closed loop feedback controlLaser Beam sampler
LT Controller
1. Laser output is sampled and turned into an electronic signal
2. Signal is compared by the controller to the set value
3. Controller makes a decision whether to change the laser resonator.
4. Command is sent to laser to change or maintain the laser resonator.
5. Different from the traditional “dithering” approach: Piezo only moves to correct the residual drift of the well-stabilized resonator. There is no artificial frequency and power fluctuation introduced by the “dither.”
www.accesslaserco.com ♦ 5603 47th Ave NE, Marysville, WA 98270, USA ♦ 360-651-6141
Find the Right Working Point - Grating Tuned Lasers
Piezo moves around the set point to stabilize length of resonator. The correct working point for grating tuned lasers is at about 10% below the peak value and more than 10% above the valley, to provide enough room for correction.
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www.accesslaserco.com ♦ 5603 47th Ave NE, Marysville, WA 98270, USA ♦ 360-651-6141
Lasy-4S with Line Tracker, an example
Input from LT controller
RF power input
45 deg beam sampler assembly
Signal output to LT Controller
www.accesslaserco.com ♦ 5603 47th Ave NE, Marysville, WA 98270, USA ♦ 360-651-6141
Lasy-4S with Line Tracker, small angle sampling
Input from LT controller
RF power input
Small angle Beam sampler assembly
Signal output to LT Controller
www.accesslaserco.com ♦ 5603 47th Ave NE, Marysville, WA 98270, USA ♦ 360-651-6141
The LT ControllerPush buttons (black):
•Mode SEL: Switch to pen loop or close loop
•Profiling: scan for a profile of power pattern
•Scaling: Auto gain control
•Up: Open loop mode- manually increase driving voltage. Close loop mode-manually increase power.
•Down: Open loop mode-manually decrease driving voltage. Close loop mode- manually decrease power.
LED’s
•Top red: Power indicator
•Closed Loop: Red-searching, Green-locked.
•Open Loop: Lights up in open loop mode
•Profiling: Blinks during profiling
•Signal LVL: fast blinks all the time. Green-power too low; Red- Power too high; Amber-Power OK
www.accesslaserco.com ♦ 5603 47th Ave NE, Marysville, WA 98270, USA ♦ 360-651-6141
LT Controller connectionsRS-232 to computer DB-9 male
HV to piezo on laser
Input from 12 V DC supply
Input from Sampler
BNC
OEM interface/ test connections DB-9 male
www.accesslaserco.com ♦ 5603 47th Ave NE, Marysville, WA 98270, USA ♦ 360-651-6141
Monitoring Status of Laser and LT Controller
Pin-5Pin-1
Pin-6 Pin-9
Pin-1: HV monitor (analog)
Pin-2: Scale-Over (digital)
Pin-3: Mode (digital)
Pin-4: Tracking (digital)
Pin-5: Ground
Pin-6: Scale-Under (digital)
Pin-7: Power (Analog)
Pin-8: Searching (digital)
Pin-9: reserved
Note: All pins are output
www.accesslaserco.com ♦ 5603 47th Ave NE, Marysville, WA 98270, USA ♦ 360-651-6141
Computer interface: Line Tracker Software
Press this start arrow to activate the program
Select the appropriate serial port before activating the program
It is a good idea to keep the power level at 700 or higher for high system resolution.
NOTE: All functions of the LT controller are available here in the Line Tracker software. Some functions of the Line Tracker software are not available in the LT controller.
www.accesslaserco.com ♦ 5603 47th Ave NE, Marysville, WA 98270, USA ♦ 360-651-6141
Computer interface /data loggingBoth power and voltage are set to a full range of 0 to 1024, arbitrary units.
When AutoSave is on files are saved as filled, with a time stamp in the file name. Data files are .csv format for easy importing into Excel.
Laser is stabilized in the close-loop mode by moving the length of the resonator along the falling edge or the rising edge.
Scale factor in effect
If manual setting is not entered by pressing the return key it will not take effect
File size indicates the number of data sets per file. Maximum 3600.
Make sure to select the appropriate serial port before starting operation
www.accesslaserco.com ♦ 5603 47th Ave NE, Marysville, WA 98270, USA ♦ 360-651-6141
Close loop operationAfter profiling this yellow setting line becomes a cross. Move the cross to approximately 10% below the desired peak on the power curve, select the appropriate edge, then press the “start tracking” button. The laser will start to be tracked and stabilized.
Notice that the piezo voltage (blue curve) moves up and down to keep the laser power (red curve) steady.
www.accesslaserco.com ♦ 5603 47th Ave NE, Marysville, WA 98270, USA ♦ 360-651-6141
Line Tracker- Auto Version•With this version of software chose Closed loop on the control box and the system starts to search for a lockable position
When it finds a lockable position it goes into closed-loop mode.
When the piezo reaches end of travel it will restart searching for a lockable position. During this time an “out of lock” signal is given from the controller and displayed on the screen.
This version of software does not allow control from computer. All controls are performed from the controller box. The software allows for display and data logging.