Photonics Teaching Kit

A recent development at Omega Optical - Photonics Teaching Kit combines practical hands-on experience with the fundamental principles of electromagnetic radiation. The kit includes 12 lab activities based on various topics within the field of photonics including solar cells, reflection, refraction, wave interference, LEDs, light detection, complementary colors, fluorescence, and phosphorescence.

COLOR PERCEPTION : Utilize several different white light sources and explore not only how the human eye perceives color, but different methods on how to create color. The roles and wavelength sensitivities of the different types of photoreceptive cone cells contained in the retina are examined. Use interference filters to demonstrate the principles of additive and subtractive color as schemes used to create the vast array of colors we see produced in movies, color printers, photographic dyes, etc.

COMPLEMENTARY COLORS; INTERFERENCE FILTERS : Learn about light's possible interactions with a physical boundary: transmission, reflection, refraction, or absorption. As the concept of interference filters is discussed, you will use a two-color filter to visualize how colors can vary depending on whether the incoming light is transmitted through the boundary, or reflected from it. Explore the differences between an absorption filter and an interference filter and how the angle of incidence of the incoming ray plays a role in how each type of filter interacts with light.

REFLECTION AND REFRACTION : A bright white sheet of paper and a bathroom mirror both reflect about the same amount of light. Why can you see an image of yourself in the mirror but not in the paper? Why does a glass prism separate light into a rainbow of colors but a glass window does not? In this exercise you will explore the laws of reflection and refraction (Snell's Law) using a laser pointer and substances of differing refractive indices (air and water). The concepts of TIRF (Total Internal Reflection) and the critical angle are explored and the use of these phenomena is discussed.

FLUORESCENCE AND PHOSPHORESCENCE : These physicochemical properties have been exploited in countless products and across a broad spectrum of disciplines, from lasers, room lighting to glow in the dark posters and invisible ink pens. You will explore what causes the phenomena and why they exhibit different characteristics. Also examined is the relationship of emitted photons and electrical current using the multi-meter.

POLARIZATION : LCDs used in computer monitors, iPods and cell phones all use the properties of polarization to generate the contrast needed to view the displays, yet few people are aware that just by removing the imbedded polarizing filters the unit is rendered useless. This lab introduces the concepts of parallel and perpendicular polarization, birefringence, and Brewster's Angle. Using a laser pointer, polarizing filters, and a multi-meter, you will discover:

• how different polarization states can be made to transmit or reflect off the same surface simply by changing the orientation of the surface
• if the incoming light is polarized or not
• how the energy striking a light sensitive LED changes depending on the angle of incidence of the incident light source.

SOLAR ENERGY : Harnessing the energy of the sun by direct capture of light striking the Earth's surface has largely been an untapped resource. In order to harvest this energy, the use of photovoltaic cells is required. In this exploration you will learn about band gaps, the conduction and valence bands, and the basics of photocell design. Using filtered light of differing wavelengths you will measure the amount of energy captured by a typical solar cell and a blue LED and draw conclusions about each band gap. You will also learn about measuring the efficiency of a photocell by plotting an IV curve and finding the fill factor of the cell.

LIGHT EMITTING DIODES : LEDs are a remarkably simple device composed of only two layers of semi conductive material. The functions of the two, the n and the p-type semiconductor layers, are covered. In this lab you will use a homemade spectroscope to examine the spectra of several different LEDs and discover how an LED is not only a light emitting device, but a light detecting device as well. The use of interference filters demonstrates how not all LEDs respond to the same wavelengths of light.

INTERFERENCE : The wave particle duality nature of light is one of the more fascinating discoveries in the field of photonics. In this lab the classic two-slit experiment is replicated using a monochromatic light source and diffraction slit.

FIBER OPTICS : In this exercise, you will uncover the mystery of light transmission through a fiber. The fibers construction and the refractive index differences in the materials contribute to loss in transmission. LED light moving through a multimode optical fiber measures the efficiency of the transmission.

The comprehensive labs are organized and supported with all required hardware for the following:

• wave/particle duality of light
• interactions of light and matter including scattering, reflection, refraction, fluorescence and phosphorescence
• relationship between the electronic structure of an atom or molecule and its emission and absorption spectra
• how light can be used to encode information by changing intensity, spectral characteristics or polarization
• how information about the structure of a molecule can be elucidated using spectroscopy
• principles behind optical computing
• human and animal perception of color
• principles behind the operation of LEDs, solar cells, and fiber optic cables are explored

The Photonics Kit includes:

• Tools for 6 groups
• 56 different optical interference filters
• 25 light sources including laser diode, light emitting diode (LED), fluorescence, incandescence and atomic emission
• 6 of 3.5 digit digital multi-meter; sensitivity to .001 mA and .001 V
• Assorted mounting hardware to assemble components
• License to reproduce 12 lesson plans
• Instructor plans with supporting notes
• Chart of the electromagnetic spectrum
• Wooden storage chest