Video Demonstrations in Lasers and Optics

Demonstrations in physical optics

VIDEOS	DESCRIPTIONS
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
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
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
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
Optical isolator	Need for an optical isolator Demonstration of the performance of an optical isolator using a quarter-wave plate and a linear polarizer
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
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
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
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
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
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
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
Fringe contrast — vibrations	Demonstration of two-beam interference in a Michelson interferometer with collimated beams Effect of vibrations on fringe contrast
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
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
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
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
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
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
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
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
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
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
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
Fraunhofer diffraction — thin wires	Demonstration of Fraunhofer diffraction by a thin wire Demonstration of Fraunhofer diffraction by thin wires with different diameters
Fraunhofer diffraction — rectangular aperture	Demonstration of Fraunhofer diffraction by a fixed rectangular aperture Demonstration of Fraunhofer diffraction by an adjustable rectangular aperture
Fraunhofer diffraction — circular apertures	Demonstration of Fraunhofer diffraction by a circular aperture Demonstration of Fraunhofer diffraction by circular apertures with different diameters
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
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
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
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
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
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