This is a argon/krypton 'whitelight' laser, which is set up to output red, green, and blue wavelengths at the same time, from a single laser cavity! It is currently outputting 7 blue lines (argon) 2 green lines (one argon, one krypton) and 2 red lines (both krypton), at about 110mw total, which is below the rated spec of 300mw (most likely due to lots of hours on the tube). Here is a picture of the beam after being deflected through a diffraction grating, and a version of it which has been labeled with the wavelengths (in nm):
Here is a beam shot after going through a Polychromatic Acousto-Optic Modulator (PCAOM), (currently set to select one red, one green, and one blue line, as can be seen in the diffracted beam), and the beam coupled into a fiber.
The PCAOM works by setting up a standing acoustic wave in a crystal of tellurium diode (TeO2), using a lithium niobate (LiNbO3) transducer. This creates a slight modulation of the optical properties of the crystal, which in turns causes a bragg reflection of certain wavelenghts, depending on the electrical drive waveform. This particular crystal is designed for operation in the visible range, and can diffract with approximately 80% efficiency. The driver is capable of outputting 8 independent frequencies (each of which diffracts a different wavelength), so it is only possible to diffract up to 8 of the 11 lines that the laser is currently operating on, so I am currently throwing away 3 of the lower power blue lines, which gives about a 75% overall efficiency. This system has a number of advantages over the modern day system of controlling the driver current to a laser directly, in particular with DPSS lasers, because the response is extremely fast (rise times of much less than one microsecond), fairly linear, extremely repeatable, and the colors in the beam are perfectly aligned in space, with the same round spacial profile, etc, which makes it perfect for laser show applications.
Here is a picture of the driver, and a closeup of the PCAOM:
There is a ton of information about argon and krypton ion lasers at Sam's Laser Faq, and there is a bit of information about this particular laser at this thread on the photonlexicon forums. If you still have questions, I can be contacted at firstname.lastname@example.org