In this paper, a simple method is described for visually demonstrating that the wavelength of light reduces when entering a medium of higher refractive index. When a violet laser (405 nm) is reflected off the surface of a Blu-ray disc (track spacing 320 nm) diffraction cannot occur since the wavelength is greater than the track spacing. However,…

The refractive index is a number that governs how light changes its direction of propagation as it enters one material medium from another. This phenomenon is known as refraction and the angles of incidence and refraction of light, referred to the normal to the interface of the two media at the point of incidence, are related by Snell's law. The…

The laser pointer has been widely used to demonstrate some simple optics phenomena, like reflection, refraction, total reflection, and diffraction. However, the rays of laser light cannot be seen in the air because the scattered light is too weak. Many physics teachers use milk or smoke to visualize rays of laser light in physics labs, but it is…

Raman scattering is a powerful tool for revealing the vibrations of molecules, but as a nonlinear optical phenomenon, its signals can change via mechanisms like resonance enhancement that have no direct analogue in infrared spectroscopy. In this work, complementary measurements conducted on 4-nitrophenol and its conjugate base allow students to…

Ultrafast laser spectroscopy is a valuable and increasingly accessible technique for studies of rapid chemical reactions. Critical to ultrafast spectroscopy is the concept of mode locking, a technique that enables a fixed phase relationship between laser modes, resulting in laser pulses with very short duration (in the fs or ps range). Despite the…

This article describes a simple way to introduce nanomaterials using the presence of carbon nanodots (CNDs) in widely available food. Budweiser® beer and Coca-Cola®, commercial foods that are commonly accessible, were utilized to demonstrate the optical property of nanoparticles. Specifically, green and violet laser pointers were employed for the…

This paper presents a new way to demonstrate the principle behind mirages in air in the lab. The setup is simple and includes a modified laser illuminator that allows direct comparison between the deflected light rays and their straight path.

In this paper, we present simple demonstrations aimed at explaining the fundamental principles of the photoacoustic effect. To display the audible phenomenon that occurs as laser radiation gets absorbed by ethene gas, an optical chopper was used to modulate the power of a continuous-wave laser whose beam was directed into a gas. The absorbed…

The purpose of this study is to use the matrix laser teaching aids to teach in the moon observation unit to explore the effectiveness of science learning of elementary school students. The subjects of the study were 367 fourth-grade students in an elementary school in New Taipei City, including 154 students in the experimental group and 213…

The Arduino board and its communication with several sensors are becoming more and more popular in the physical science community. They offer inspiring possibilities for learning different physical concepts. In this article, we focused on creating a very practical educational system for experimenting with diffraction of laser light and graphically…

This article illustrates a learning sequence from the Interdisciplinary Mathematics and Science (IMS) Learning project, connecting science and mathematics learning in the primary school. Exploring light and its properties involved a series of investigations conducted in Grades 4 and 5 across three classes in two schools in regional Victoria. The…

Students often have difficulties comprehending situations in which wave characteristics of light are manifested. After teaching wave optics, we studied the level of understanding of reflective diffraction of light with a group of secondary school students, and the phenomenon of diffraction in general. We analysed the possibility of using…

A pair of galvo mirrors reflecting light from a laser pointer is suggested for use as a school demonstration of Lissajous figures. The device is small, cheap and easy to assemble. Combined with a two-channel waveform generator, a full spectrum of excellently stable Lissajous figures can be generated (concerning frequency ratio, amplitude ratio and…

We have developed a laboratory project in which students prepare liposomes, expose them to hyperosmotic and hypoosmotic solutions, and follow the resulting shrinking and swelling (respectively) with laser light scattering. Each light intensity transient can be fit to an exponential decline or rise, with the decay constant (k) and the amplitude…

The Kaleidophone, invented by Charles Wheatstone (1802-1875) in 1827, is a delightful mixture of physics and art. A typical example of the device, dating from the latter part of the 19th century, is shown in Fig. 1. The upright rods, which are approximately 25 cm in length, are of variously circular, oval, square, and rectangular cross section,…