Standard Operating Procedure
Coherent Innova-90 Argon-Ion Laser

 

Innova-90 Laser

Introduction

This Standard Operating procedure applies to the Coherent Innova-90 argon-ion laser housed in Niagara College's High Power Laser Lab (V12). This class-IV laser features either multiline output (up to six wavelengths simultaneously) or single-wavelength with the use of the prism wavelength selector.

Statistics

Manufacturer: Coherent, Inc.
Type: Argon-Ion
Class: IV
Maximum Rated Power: 12 Watts CW
Wavelength Range (in current configuration): 454.5nm to 528.7nm
Cooling: Flowing Water, 2.2 gpm
Power Source: Three-Phase, 208V, 45A per phase

Hazard Analysis

Report ID: "Innova-90 Argon"
Performed On: 2009/07/02
by Laser Safety Officer: D. Turnbull
Input Data: 454.5nm (shortest wavelength), CW, 3.0W, 0.25s exposure
Beam Diameter: 1.5mm
Small Source Ocular MPE: 2.55E-03W/cm2

Worst Case Optical Density: 3.49 OD (3.71 OD if 5W worst-case used)
Intrabeam Eye NOHD: 9.7E+02m
Small Source Eye Diffused Reflection NHZ: 0.88m

Operating Procedure

Revised 2004/01/16 by M. Csele

STARTING the laser

  1. Don safety glasses suitable for an argon laser. These glasses must have an OD of at least 4 at both 488nm and 514nm.
  2. Turn the cooling water supply ON. The valve is located behind the laser. Verify water flow if required by observing the output line to the drain (under the table).
  3. If not already on, turn the three-phase supply (breakers in the black panel) ON.
  4. Turn the LOCK switch on the laser control. The FAULT light and the WATER FLOW light will come on for a moment and should then disappear. If they do not disappear water flow is insufficient and this situation must be corrected before proceeding.
  5. Ensure the AUTO START button is selected.
  6. Adjust the WAVELENGTH SELECTOR on the control to read '514' if using broadband (multiline) optics. When using single-line optics, adjust the WAVELENGTH SELECTOR to the wavelength in use (note that this only affects output power - if an external power meter is used, this step may be optional).
  7. Push the POWER RANGE button corresponding to the desired power range for the experiment (e.g. use the 0.5 Watt range when operation with a 400mW beam output is desired).
  8. Ensure that the anticipated path of the output beam is terminated in a beam stop or into the optics of an experiment in progress.
  9. Depress the ON pushbutton. The controller will display 'START DELAY' for 30 seconds during which time the cathode will preheat to operating temperature.
  10. The laser will start automatically. If a beam is not visible either (a) the shutter is not open, (b) the current is too low to allow lasing, or (c) the optics are misaligned.
Innova-90 Controller

SHUTDOWN

  1. Depress the OFF pushbutton. Lasing will cease immediately.
  2. Turn the LOCK OFF to remove power from the laser
  3. LEAVE the WATER ON for one minute to remove latent heat from the laser the turn the water OFF

NORMAL OPERATING CONDITIONS

  1. With the laser running and optics optimized, set the LIGHT REG control for desired output power. The CURRENT CONTROL is usually set fully clockwise to allow full output. The indicator light for the LIGHT mode will be lit indicating the laser is in this mode.
  2. For experiments involving a specific tube current set the LIGHT REG control fully clockwise (to allow maximum output) and use the CURRENT CONTROL to adjust output. The CURRENT mode indicator light will be lit. It may be necessary to select a new range to allow the laser to reach full current.

CHANGING OPTICS

To begin, set the tube current for 30A. The laser will be in current-regulate mode.
Always align arrow first with the dot on the holder as per the photograph, insert fully into the bayonet mount in the rear of the laser, then twist CW to lock the optic into the laser. The arrow on the laser will align with the second dot on the optic holder when properly installed. Multiline (ML) and single-line (SL) optics are identified as per the photographs below.

Innova-90 Optics
In the case of the multiline optic, grasp the outside barrel of the optics holder, not the inside knurled portion which holds the actual optic. In the case of the single-line optic, grasp the can itself, not the two small nuts.

From multiline (broadband) to single line

  1. Adjust the wavelength knob CLOCKWISE (increasing wavelength shown on the dial) past 800 to 400 then to the calibration for the 488nm line (see the chart below)
  2. Adjust the horizontal control (lower left) CCW two turns until lasing begins
  3. Tune both controls for maximum power
SL Optics

From Single line to Multi-Line (broadband)

  1. Adjust the wavelength know CCW (decreasing wavelength shown on the dial) below 400, past 800 anddown to 675nm
  2. Adjust the horizontal control CW about two turns until lasing begins
  3. Tune both controls for maximum power
ML Optics

Current calibration (2004/01/16)

Actual Wavelength (nm) Wavelength Indicated (nm)
514.5540
501.7524
496.5521
488.0512
476.5500
479

OPTIMIZING OPTICS

  1. Preselect a LASER POWER RANGE
  2. Set the CURRENT REG control to give a LASER POWER indication about half-way through the range
  3. Set the LIGHT REG control fully clockwise (Maximum) to put the laser in current regulation mode.
  4. Adjust the Horizontal control on the back of the laser (the smaller black knob to the lower left) to obtain maximum output power on the meter
  5. Adjust the wavelength selector control (Vertical control) on the back of the laser to obtain maximum output power on the meter
  6. Press the 'TUNE 5X' button on the control and perform steps 4 and 5 above again
Copyright (C) Niagara College, Canada, 2003-2004
This page is part of the PHTN1430 Course Page