Standard Operating Procedure
Laboratory Dye Laser

Laboratory Dye Laser
Figure 1: Dye Laser Components

Introduction

This Standard Operating procedure applies to the dye laser housed in Niagara College's High Power Laser Lab (V12). This class-IIIb laser can operate with a variety of dyes to lase in multiple ranges in visible region of the spectrum.

Statistics

Manufacturer: Niagara College
Type: Dye
Class: IIIb
Maximum Rated Output Power: 100mW with 400mW of pump input
Wavelength Range (Rhodamine-6G): 560nm to 650nm
Wavelength Range (7-diethylamino-4-methylcoumarin): 438nm to 482nm
Pump Source: Lumonics Excimer-500 Laser running N2/He mixture (337.1nm)
Note that all ANSI safety controls are provided by the pump laser system and related interlocks

Operating Procedure

Revised 2004/04/16 by M. Csele

SETUP of the dye cell

  1. Don safety glasses suitable for the species being used with suitable optical density over the wavelength range of the dye as well as an OD of at least 3 at the pump wavelength of 337.1nm.
  2. Start the Excimer-500 laser according to the SOP for that laser. Note that pulse-to-pulse repeatability in the pump laser is enhanced by passivation with the gas mixture for 12 hours before use. Use of a lower-than-normal pressure of 20 psig and a high voltage setting of 30kV is recommended for use as a pump laser.

  3. CAUTION: Dye solutions are TOXIC, can be absorbed through the skin, and will cause permanent stains on most materials.
  4. Wearing nitrile gloves rinse the dye cell with pure methanol in the sink in V14
  5. Pour the solution from the storage bottle into a small beaker then load the dye cell with 6ml of premixed dye solution. Pour unused solution back into the storage bottle.
  6. Rinse the beaker with pure methanol
  7. Load the dye cell into the holder in the laser like that in figure 2 below. Place a small square of foam under the cell then gently lower the clamp on top of the cell and tighten the clamp screw until the cell is tight. Do not overtighten the clamp as the cell is fragile and valued at $250.00

Laboratory Dye Laser Cell Detail
Figure 2: Details of the Dye Cell Mount

OPTICS ALIGNMENT (using an HR)

  1. Start the Excimer-500 pump laser at a low pulse rate of 2Hz
  2. Adjust the cylinder lens (by sliding the mount) to focus the pump light onto the dye cell until superradiant lasing is generated
  3. Using a card with a small hole in it allow light emitted from the dye cell to pass through the hole and towards the HR
  4. Align the HR mirror so that the reflected beam is reflected back into the cell
  5. Observe the output beam and align the HR so that the center becomes more powerful and collimated
  6. Repeat the procedure for the OC
  7. Shift the position of the pump lens until the laser is operating in a 'normal' mode and is no longer superradiant.
  8. Verify proper alignment of the HR by blocking the intra-cavity beam between the dye cell and the HR at which point the output beam should disappear if it was aligned properly
  9. Blocking the beam between the cell and the OC should produce the same result of causing ascillation to cease
  10. If a diffraction grating is employed in place of the HR mirror, align it in a similar manner however an order of the grating must be used such that tunability is achieved (i.e. not zeroth order)

CLEAN-UP of the dye cell

  1. If dye is still 'fresh', dump dye back into the storage bottle
  2. If dye volume has reduced due to evaporation from the cell, do not reuse it but rather dump used dye in V14
  3. Rinse the dye cell with pure methanol

Copyright (C) Niagara College, Canada, 2004
This page is part of the PHTN1430 Course Page