TOPICS | DESCRIPTIONS | VIDEOS |
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Overview of demonstrations in lasers and optics | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) | |
I. Demonstrations in physical optics | ||
Optics: polarization of light and polarization manipulation | ||
Linear polarizer | Description of a linear polarizer Use of a linear polarizer to analyze the state of polarization of light from a laser Demonstration of the change in the state of polarization of light after reflection by two aluminum coated mirrors Use of a linear polarizer to set the state of polarization of light | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Polarization rotation using polarizers | Rotation of the plane of polarization of light using a single linear polarizer Limitation of the single polarizer method Rotation of the plane of polarization using two linear polarizers Effect of polarization rotation on transmitted intensity | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Quarter-wave plate | Description of a quarter-wave plate Use of a quarter-wave plate to change the state of polarization of light, e.g., from linear to elliptical (or to circular) polarization Demonstration that there is no change in the state of polarization when propagating along either principal axis of the quarter-wave plate | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Half-wave plate | Description of a half-wave plate Use of a half-wave plate to rotate the plane of polarization from zero to ninety degrees with very little loss Demonstration that there is no change in the state of polarization when propagating along either principal axis of the half-wave plate | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Optical isolator | Need for an optical isolator Demonstration of the performance of an optical isolator using a quarter-wave plate and a linear polarizer | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Scattered light in a dielectric | Propagation of linearly polarized light in a dielectric (Lucite) rod Observation of Rayleigh scattered light within rod Demonstration that the state of polarization of the scattered light is the same as that of the incident light | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Optics: reflection at dielectric interfaces | ||
Reflection at the air-glass boundary | Reflection and transmission of light at an air-glass boundary as a function of the angle of incidence (0-90º) for different states of polarization of the incident light Demonstration of Brewster's angle | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Reflection at the glass-air boundary | Reflection and transmission at a glass-air boundary as a function of angle of incidence (0-90º) for different states of polarization of the incident light Demonstration of the critical angle Demonstration of the propagation of the transmitted beam along the boundary at the critical angle Demonstration of Brewster's angle | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Phase shifts in total internal reflection | Demonstration of the absence of any change in the state of polarization of the reflected and transmitted light at a glass-air boundary below the critical angle Demonstration of the change in the state of polarization of reflected light at a glass-air boundary above the critical angle, i.e., in total internal reflection Application of this effect to making quarter-wave and half-wave plates | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Optics: two-beam interference | ||
Two-beam interference — collimated beams | Demonstration of two-beam interference using collimated beams in a Michelson interferometer Demonstration of various fringe patterns as a function of the alignment of the interferometer mirrors Effect of mirror translation on fringe pattern using a piezoelectric driver | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Two-beam interference — diverging beams | Demonstration of two-beam interference using diverging beams in a Michelson interferometer Demonstration of various fringe patterns as a function of the alignment of the interferometer mirrors Change in fringe pattern as a function of path length difference | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Destructive interference — Where does the light go? | Demonstration of constructive and destructive interference in a Michelson interferometer using diverging beams Demonstration of complete destructive interference between the two beams leaving the interferometer for equal path lengths Where does the light go in destructive interference? Demonstration that there is light in each arm of the interferometer in destructive interference Demonstration of light reflected back toward source simultaneously with light transmitted from interferometer for equal paths and also for unequal paths of the interferometer | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Fringe contrast — vibrations | Demonstration of two-beam interference in a Michelson interferometer with collimated beams Effect of vibrations on fringe contrast | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Fringe contrast — intensity ratio | Demonstration of two-beam interference in a Michelson interferometer with collimated beams Effect of intensity difference between interfering beams on fringe contrast | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Fringe contrast — polarization difference | Demonstration of two-beam interference in a Michelson interferometer with collimated beams Determination of the state of polarization in each arm of the interferometer Demonstration of the rotation of the plane of polarization in one arm of the interferometer using a quarter-wave plate Demonstration of the effect of polarization difference on fringe contrast, showing zero contrast for orthogonal polarizations | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Fringe contrast — path difference | Demonstration of two-beam interference in a Michelson interferometer with collimated beams Demonstration of the effect of path length difference (0-100 cm) on fringe contrast Demonstration of the spectrum of the light source, in this case, a multilongitudinal mode He-Ne laser Relationship between fringe contrast, path length difference, and spectrum of the light source | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Coherence length and source spectrum | Demonstration of two-beam interference in a Michelson interferometer with collimated beams Demonstration of fringe contrast with path length difference for a single-frequency laser light source Demonstration of fringe contrast with path length difference for two- and three-frequency laser light sources Relationship between fringe contrast and coherence length | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Optics: multiple beam interference | ||
Plane mirror cavity — collimated beams | Demonstration of multiple beam interference using a plane mirror cavity in transmission with mirror separation of 3 mm and collimated incident beam Observation of finesse, free spectral range, and effect of cavity misalignment Demonstration of multiple beam interference in reflection using the same cavity Simultaneous observation of multiple beam interference in transmission and in reflection | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Plane mirror cavity — diverging beams | Demonstration of multiple beam interference using a plane mirror cavity in transmission with a mirror separation of 3 mm and a diverging incident beam Demonstration of multiple beam interference in reflection using the same cavity Simultaneous observation of multiple beam interference in transmission and in reflection | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Curved mirror cavity — radial modes | Demonstration of multiple beam interference in transmission using a cavity with curved mirrors and a single-frequency laser light source Observation of the intensity distribution associated with a variety of radial (or transverse) modes as a function of cavity tuning Observation of the cavity transmission associated with radial modes as a function of cavity tuning Demonstration of the properties of a confocal resonator, i.e., where the radius of curvature of each mirror is equal to the mirror separation Demonstration of the behavior just below and just above the confocal condition | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Optical spectrum analyzer | Demonstration of the use of a confocal cavity for the spectral analysis of single-frequency laser Demonstration of the use of a confocal cavity for the spectral analysis of multifrequency laser | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Optics: Fraunhofer and Fresnel diffraction | ||
Fraunhofer diffraction — adjustable slit | Demonstration of Fraunhofer diffraction by a narrow slit Demonstration of Fraunhofer diffraction by an adjustable narrow slit | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Fraunhofer diffraction — two slits | Demonstration of Fraunhofer diffraction by a single slit Demonstration of Fraunhofer diffraction by pairs of 150 μm slits with spacings ranging from 150 μm to 2 mm | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Fraunhofer diffraction — multiple slits | Demonstration of Fraunhofer diffraction by a single slit Demonstration of Fraunhofer diffraction by two slits Demonstration of Fraunhofer diffraction by three slits Demonstration of Fraunhofer diffraction by four, five, six, seven, eight, nine, and more slits Demonstration of Fraunhofer diffraction by multiple slits with line spacings of 100 per inch, 200 per inch, 300 per inch, and 2000 per inch Demonstration of Fraunhofer diffraction by multiple slits as a function of slit orientation | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Fraunhofer diffraction — thin wires | Demonstration of Fraunhofer diffraction by a thin wire Demonstration of Fraunhofer diffraction by thin wires with different diameters | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Fraunhofer diffraction — rectangular aperture | Demonstration of Fraunhofer diffraction by a fixed rectangular aperture Demonstration of Fraunhofer diffraction by an adjustable rectangular aperture | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Fraunhofer diffraction — circular apertures | Demonstration of Fraunhofer diffraction by a circular aperture Demonstration of Fraunhofer diffraction by circular apertures with different diameters | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Fraunhofer diffraction — crossed multiple slits | Demonstration of Fraunhofer diffraction by fixed crossed multiple slits Demonstration of Fraunhofer diffraction by crossed multiple slits as a function of the relative orientation of the slits | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Fresnel diffraction — adjustable slit | Demonstration of Fresnel diffraction by a fixed slit Demonstration of Fresnel diffraction by an adjustable slit Observation of the transition from Fresnel to Fraunhofer diffraction using an adjustable slit | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Fresnel diffraction — circular apertures | Demonstration of Fresnel diffraction by a circular aperture using a spatially filtered laser source Demonstration of Fresnel diffraction by circular apertures with different diameters Demonstration of Fresnel diffraction by a circular aperture as a function of source distance | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Optics: propagation in optical fibers | ||
Single mode fiber | Demonstration of a single mode fiber and light coupling into the fiber Demonstration of single mode transmission Demonstration of the effect of stress and bends applied to fiber showing light expelled by fiber Demonstration of the effect of bends and stress on single mode transmission | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Multi-mode fiber | Demonstration of light transmission through a multimode fiber, showing a variety of transverse modes Demonstration of the effect of input alignment changes on transverse modes Demonstration of the effect of fiber bends and stresses on transverse modes Demonstration of single mode behavior in a multimode fiber using fiber bends to eliminate higher order transverse modes | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Polarization in a single mode fiber | Demonstration of single mode propagation in an optical fiber Demonstration of the state of polarization of the light exiting the fiber as a function of stress and bends applied to the fiber | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
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 | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
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 | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
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 | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
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 | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
Light inside and light outside laser | Demonstration of light inside laser cavity being much stronger than light leaving the laser Discussion of cavity dumping | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
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 | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
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 | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
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 | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
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 | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
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 | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
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 | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
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 | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
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 | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
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 | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |
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 | Streaming: (RM - 56K) (RM - 220K) Download: (MP4) |