RES.6-006 | Spring 2008 | Undergraduate
Video Demonstrations in Lasers and Optics

Demonstrations in laser fundamentals

VIDEOS DESCRIPTIONS
II. Demonstrations in laser fundamentals
Laser fundamentals I
Simple laser

Introduction to lasers

Demonstration of a simple laser with internal mirrors

Demonstration of a laser with external mirrors, showing the effect of cavity misalignment

Light amplifier

Demonstration of light amplification by an optical amplifier, using a He-Ne laser and a He-Ne amplifier tube

Demonstration of 6% amplification per pass

Calibration of detector using a fixed loss

Measurement of the effect of amplifier fluorescence on detector output

Polarization of laser light

Demonstration of the state of polarization of a laser with external mirrors and the amplifier terminated with Brewster windows

Demonstration of the state of polarization of a laser with internal mirrors

Spectrum of laser light

Demonstration of the spectrum of laser light from a He-Ne laser with external mirrors showing multiple frequencies associated with longitudinal modes of the cavity

Demonstration of the polarization of the multiple frequencies being identical

Demonstration of the effect of temperature, vibration, and misalignment of the spectrum of the laser output

Demonstration of the spectrum of laser light from a He-Ne laser with internal mirrors, showing multiple frequencies associated with longitudinal modes of the cavity

Demonstration of the polarization of the multiple frequencies from an internal mirror laser showing that adjacent modes are orthogonally polarized

Demonstration of single-frequency output by polarization selection

Demonstration of the effect of temperature on the spectrum of the laser output

Light inside and light outside laser

Demonstration of light inside laser cavity being much stronger than light leaving the laser

Discussion of cavity dumping

Laser fundamentals II
Optics of laser beams

Demonstration of an expanding beam from a laser

Demonstration of spatial filtering of a laser beam

Demonstration of laser-generated speckle patterns on screen

Visualization of laser beam propagating in a water tank

Visualization of focused laser beam in a water tank

Observation of the Rayleigh range

Laser transverse modes

Demonstration of various transverse modes from a laser as a function of cavity alignment

Demonstration of the use of an intra-cavity adjustable aperture to control the number of transverse modes that can oscillate

Demonstration of the frequency spectrum of laser transverse modes

Demonstration of a method of isolating single transverse modes using a wire inside the laser cavity

Demonstration of the spectrum of isolated transverse modes

Demonstration of the change in orientation of a transverse mode

Demonstration of the effect of blocking one of the lobes of a two-lobe mode inside the laser cavity

Demonstration of the effect of blocking one of the lobes of a two-lobe mode outside the laser cavity

Laser linewidth

Discussion of laser linewidth

Measurement of laser linewidth using an optical spectrum analyzer

Measurement of the fundamental laser linewidth using a two-frequency laser showing the intrinsic spectral width to be much less than 30 Hz

Laser fundamentals III
Reflection back into laser

Demonstration of the intensity and spectrum of a single-frequency laser and a multifrequency laser

Demonstration of the effect of back reflection into the laser on the intensity and the spectrum of each laser

High power argon laser

Demonstration of the operation on an argon ion laser

Demonstration of the high intensity in the argon laser beam by burning a hole in cardboard with an unfocused laser beam

Multi-wavelength argon laser

Demonstration of the operation of an argon ion laser

Demonstration of simultaneous multiwavelength operation of an argon laser in the blue-green spectral range

Single frequency argon laser

Demonstration of the operation of an argon ion laser

Demonstration of the broad spectrum from an argon laser using an optical spectrum analyzer

Demonstration of single-frequency operation using an intracavity etalon

Demonstration of the effect of etalon tuning on the single-frequency output of the laser showing mode hopping phenomena

Demonstration of the effect of aligning the intracavity etalon normal to the laser beam showing chaotic amplitude and frequency behavior

Tunable dye laser

Demonstration of the operation of a cw dye laser pumped by an argon laser

Demonstration of the wide tuning capability of the dye laser from green to yellow to red

Dye laser excitation of sodium

Demonstration of the excitation of atomic sodium in a heated cell by a tunable dye laser

Observation of intense radiation from the sodium vapor when the laser is on resonance with a ground state transition in sodium

Dye laser induced fluorescence in iodine

Demonstration of fluorescence induced by a tunable dye laser in a cell of molecular iodine

Simultaneous display of the color of the dye laser and the color of the iodine fluorescence as a function of laser tuning showing large differences in color under certain conditions