The Physics of Light and Color Interactive Tutorials

• Java Development Laboratory

  Here is an interactive tutorial where students can visit our Java development laboratory at the National High Magnetic Field Laboratory where these amazing tutorial-applets are created.

• Optical Diffraction

  Explore the diffraction of light through an adjustable slit (or aperture) by adjusting the slit width and wavelength of light to discover how these variables affect optical diffraction in this interactive tutorial.

• Interference: The Double Slit Experiment

  Discover diffraction of light through an adjustable set of double slits (or apertures) to discover how these variables affect optical diffraction and interference of the diffracted light waves.

• Electromagnetic Radiation

  Have you ever played with an electromagnetic radiation wave? Well you can with this tutorial that allows you to move the wave around in three-dimensional space. Visitors can also adjust the wavelength to see how that affects the wave.

• Jablonski Diagram

  Examine excitation and decay pathways in fluorescence, phosphorescence, and delayed fluorescence by choosing between the three phenomena and see various states that electrons pass through in returning to the ground state.

• Electron Excitation and Emission

  Examine how electrons in an atom are excited into higher energy states by photons of varying wavelengths. This tutorial permits visitors to vary the photon wavelength to propel the electrons into various energy levels.

• Optical Interference

  Interference between two light waves is a phenomenon that is often seen in soap bubbles with the wide color spectrum that they reflect. This tutorial allows students to add two light waves together and view the result.

• Optical Birefringence

  Explore birefringence or double refraction of light when passed through a crystal of Iceland spar by moving a crystal over the image of a pen and text to show how birefringence affects the refraction and polarization of light.

• Simple Magnification

  Explore how a simple magnifying glass works with this tutorial designed to explain the concept of magnification. The visitor can use the mouse cursor to move a magnifying glass to change the image enlargement of an object.

• Interactive Lens Action Tutorials

  The featured set of tutorials examines lens action as a function of lens shape. Examine the difference between negative and positive lenses on image formation and visit our variable lens Java and Flash tutorials.

• Concave Mirrors

  Learn about the reflection of an object from a concave mirror in this interactive tutorial. The student is able to move the object back and forth and view what happens to the reflected image.

• Concave Mirrors - The Virtual Image

  Examine as this interactive tutorial demonstrates to the student how a simple virtual image is created and formed on the opposite side of an object's reflection in the featured concave mirror.

• Convex Mirrors

  A tutorial that demonstrates simple image reflection of an object with a convex mirror by adjusting the position of the object with respect to the mirror to see how it affects the resulting image.

• Reflection of Light

  Explore the reflection of a single electromagnetic visible light wave by adjusting the wavelength and incident angle of the reflection to demonstrate the changes these variables can make to the wave reflection.

• Refraction of Light

  Related to the previous tutorial, this applet demonstrates how a single wavelength of light is refracted by various media by changing the index of refraction of the media, as well as the angle and wavelength of the incident light.

• Prism Refraction

  A tutorial on prism refraction allowing students to explore interactively how changes in the thickness and angle of incidence of a visible light beam affect how light is refracted by a prism.

• Human Vision

  Exploring how images are created on the retina of a human eye, this interactive tutorial allows the student to adjust the distance of an object from the eye to vary the size of the image.

• Basic Electromagnetic Wave Properties

  Explore the relationship between frequency, wavelength, and energy, and enables the visitor to adjust the intensity of the radiation and to set the wave into motion in this interactive tutorial.

• Tuning a Radio Wave Receiver

  Discover and learn how a variable capacitor is coupled to a simple antenna transformer circuit to tune a radiofrequency spectrum in this featured tutorial starting with the variable capacitor being set to a value of 50 picofarads.

• Particle and Wave Refraction

  Explore how particles and waves behave when refracted through a transparent surface. The tutorial initializes with particles of red light (photons) impacting the surface of a glass block with an angle of approximately 30 degrees.

• Particle and Wave Reflection

  Discover how particles and waves behave when reflected from a smooth surface. The tutorial initializes with particles of red light (photons) impacting the surface of a mirror with an incident angle of approximately 60 degrees.

• Particle and Wave Diffraction

  See how particles and waves behave when diffracted by an opaque surface. The tutorial initializes with particles of red light (photons) impacting the surface of a opaque light stop with an incident angle of approximately 90 degrees.

• Lightning: A Natural Capacitor

  View the build-up of static electrical charges between storm clouds and the wet ground during a thunderstorm with this tutorial, which simulates capacitor-like lightning discharges.

• Compact Disk Lasers

  See how the laser is focused onto the surface of a spinning compact disk, and how variations between the height of pits and lands determine whether the light is scattered by the disk surface or reflected back into a detector.

• Light Emitting Diodes

  Discover and learn how two dissimilar doped semiconductors can produce light when a voltage is applied to the junction region between the materials in this interactive java tutorial.

• Nd:YLF Mode-Locked Pulsed Lasers

  Many applications, such as illumination techniques in fluorescence microscopy, require a reliable power laser source enabling efficient frequency conversions. Explore the operation of a Nd:YLF multi-pass slab laser.

• Ti:Sapphire Mode-Locked Lasers

  Explore the operation of Ti:sapphire lasers over a broad range of near-infrared wavelengths with variable pulse widths and an adjustable applet speed control in this interactive java tutorial.

• Spontaneous and Stimulated Processes

  Examine spontaneous absorption and emission, as well as stimulated emission resulting in energy level transitions with this tutorial. These processes represent important concepts necessary in understanding laser operation.

• Centering the Lamp Filament

  Discover how the lamp filament is centered in a microscope and how this appears when viewed through the back focal plane of the objective or alternatively, through a piece of tissue paper placed on the field port lens.

• Speed of Light in Transparent Materials

  When light traveling in a vacuum enters a new transparent medium, speed is reduced in proportion to the refractive index of the new material. See the reduction in the speed of light as a function of refractive index in substances.

• Specular and Diffuse Reflection

  The amount of light reflected by an object, and how it is reflected, is highly dependent upon the smoothness or texture of the surface. Explore how light waves are reflected by smooth and rough surfaces in this tutorial.

• Antireflection Surface Coatings

  One of the most significant advances made in modern lens design is the significant improvement in antireflection coating technology. See various coatings and their reflectivities as a function of incident angle.

• Common Reflecting Prisms

  Most reflecting prisms are designed to be located in orientations where entrance and exit faces are parallel and perpendicular to the optical axis. Examine image deviation, rotation, and displacement exhibited by reflecting prisms.

• Right-Angle Prisms

  Explore light reflection and image rotation, inversion, and reversion by a right-angle prism as a function of the prism orientation with respect to incident light in this interactive tutorial.

• Concave Spherical Mirrors

  Explore how moving an object farther away from the center of curvature affects the size of the real image formed by the mirror as well as the effects of moving the object closer to the mirror at various points to form a virtual image.

• Convex Spherical Mirrors

  The image result of an object reflected by a convex mirror is typically virtual, upright, and smaller. Discover how moving the object farther away from the mirror's surface affects the size of the virtual image formed behind the mirror.

• Concave Spherical Mirrors (3-Dimensional Version)

  Discover how moving the object farther away from the center of curvature affects the size of the real image formed by the mirror in this interactive tutorial.

• Convex Spherical Mirrors (3-Dimensional Version)

  Examine how moving an object farther away from the mirror's surface affects the size of the virtual image formed behind the mirror with three-dimensional graphics.

• The Critical Angle of Reflection

  Discover the transition from refraction to total internal reflection as the angle of the incident wave is increased at constant refractive index in this featured interactive java tutorial.

• Observing Objects in Water

  Objects seen in the water will appear to be at a different depth than it actually is, due to the refraction of light rays. Discover how fish, observed from the bank of a pond or lake, appear to be closer to the surface than they really are.

• Refraction by an Equilateral Prism

  Explore how the incident angle of white light entering the prism (also known as dispersion) affects the degree of dispersion and the angles of light exiting the prism in this interactive tutorial.

• Beam Steering by Wedge Prisms

  Prisms positioned at slight angles with respect to each other are termed optical wedges, and deflect light by refraction rather than reflection. Examine how two wedge prisms operate together to deflect an incident light beam.

• Refraction of Monochromatic Light

  Discover how changes to the incident angle and refractive index differential between two dissimilar media affect the refraction angle of monochromatic light at the interface in this interactive tutorial.

• Human Eye Accommodation

  Learn about human eye accommodation as the user explores changes in the lens structure as objects are relocated with respect to the eye in this interactive java tutorial.

• Photosynthesis

  The process of green plants synthesizing numerous complex carbon-based biochemicals used to sustain life is called photosynthesis. This tutorial demonstrates the basic molecular steps in the photosynthetic process.

• Transmission and Reflection by Beamsplitters

  A beamsplitter is an optical component that partially transmits and reflects an incident light beam, usually in unequal proportions. Examine transmission and reflection of a light beam by three common beamsplitter designs.

• Solar Cell Operation

  Solar cells convert light energy into electrical energy either indirectly by first converting it into heat, or through a direct process known as the photovoltaic effect. This tutorial explores the basic concepts behind solar cell operation.

• Hydrogen Fuel Cell Basics

  Fuel cells are designed to utilize a catalyst, such as platinum, to convert a mixture of hydrogen and oxygen into water. This interactive tutorial explores the major steps in fuel cell operation.

• Avalanche Photodiodes

  An avalanche photodiode is a silicon-based semiconductor containing a pn junction consisting of a positively doped p region and a negatively doped n region sandwiching an area of neutral charge termed the depletion region.

• Reflection and Refraction with Huygens Wavelets

  Featured in this tutorial is designed to illustrate the reflection and refraction of light according to the multiple wavelet concept, now known as the Huygens' principle.

Polarized Light

• Polarized Light Microscopy with a First Order Retardation Plate

  See as this tutorial simulates the effect on specimen colors of adding a 530 nanometer retardation plate between the polarizer and analyzer in a polarizing microscope.

• Birefringence Variations with Crystal Orientation

  Observe and examine variations in birefringence that result from orientational variations between the crystal optical axis and the incident light beam in this interactive tutorial.

• Birefringent Crystals in Polarized Light

  Explore how birefringent anisotropic crystals interact with polarized light in an optical microscope as the circular stage is rotated through 360 degrees in this interactive java tutorial.

• Polarization of Light (3-D Version)

  Discover and learn more about the effects of two polarizers having adjustable transmission axes on an incident beam of white light in this featured three-dimensional interactive java tutorial.

• Nicol Prisms

  Discover the generation of orthogonal or mutually perpendicular (ordinary and extraordinary) waves as the result of light transmission through a Nicol prism in this interactive tutorial.

• Brewster's Angle

  As light passes from one medium to another, some light polarizes and reflects as a function of the refractive index of the other medium. Observe how changes in refractive index affect the amplitude and reflection angle of incident light.

• Polarization of Light

  Learn as this tutorial explains the polarization of light by allowing visitors to interactively block or pass light waves by controlling the alignment of polarizers with an incident light beam.

• Electromagnetic Wave Propagation

  Explore and examine propagation of a virtual electromagnetic wave and considers the orientation of the magnetic and electric field vectors in this interaactive tutorial.

• Fresnel or Refractive Index Ellipsoid

  The Fresnel, or refractive index, ellipsoid describes the dielectric properties measured in all directions through a material. Explore variations in the shape and dimensions of the ellipsoid as a function of refractive index.

• Michel-Levy Birefringence Chart

  The Michel-Levy Birefringence Chart interactive tutorial enables visitors to determine the interference color associated with all three values by clicking on selected regions of the interactive chart.

Primary Colors

• Primary Additive Colors

  Primary additive colors refers to the addition of equal amounts of red, green, and blue light yielding white light. Explore how the three primary additive colors interact with each other, both in pairs or all together.

• Primary Subtractive Colors

  Primary subtractive colors (cyan, yellow, and magenta) can be formed by subtracting one of the primary additives (red, green, and blue) from white light. Explore how the three primary subtractive colors interact with each other.

• Color Filters

  See how color filters operate to change the color of objects visualized under filtered illumination by dragging and dropping color filters over objects illuminated with white light and previously filtered with a primary additive colors.

• Color Separation

  Discover how individual subtractive primary colors can be separated from a full-color photograph, and then how they can be reassembled to create the original scene in this interactive tutorial.

• Color Temperature

  Explore the effect of raising the temperature of a black body radiator in this interactive tutorial. The example is a black pot that can be "heated" with a slider to raise the color temperature of the pot.

• Lasers

  Learn more about the discharge of a ruby laser with a xenon flash tube. Atoms in the laser crystal are excited by a flash tube and emit photons that are reflected back and forth between mirrors at the ends of the laser crystal.

• Moiré Patterns

  Moiré fringes arise from interference patterns that are generated when two similar grids overlap each other resulting in a series patterns that change shape as the grids are translated with respect to one another.

• Absorption Filters

  Absorption filters, made from pigmented gelatin resins, are the most common filter for brightfield and fluorescence microscopy. Examine how absorption filters pass certain wavelengths of light while blocking others.

• Ishihara Colorblindness Test

  Explore and examine this tutorial as it simulates how full-color images appear to colorblind individuals, and compares these images to the Ishihara diagnostic colorblind test.