Polarization of light and the related knowledge are key and difficult points in optical teaching, and they are difficult to be understood since they are very abstract concepts. To help students understand the polarization properties of light, some classroom demonstration experiments have been constructed by employing the optical source, polarizers, wave plates optical cage system and polarization axis finder (PAF). The PAF is a polarization indicating device with many linear polarizing components concentric circles, which can visualize the polarization axis’s direction of linearly polarized light intuitively. With the help of these demonstration experiment systems, the conversion and difference between the linear polarized light and circularly polarized light have been observed directly by inserting or removing a quarter-wave plate. The rotation phenomenon of linearly polarized light’s polarization axis when it propagates through an optical active medium has been observed and studied in experiment, and the strain distribution of some mounted and unmounted lenses have also been demonstrated and observed in experiment conveniently. Furthermore, some typical polarization targets, such as liquid crystal display (LCD), polarized dark glass and skylight, have been observed based on PAF, which is quite suitable to help students understand these targets’ polarization properties and the related physical laws. Finally, these demonstration experimental systems have been employed in classroom teaching of our university in physical optics, optoelectronics and photoelectric detection courses, and they are very popular with teachers and students.
A new type of photoelectric system structure, cage system, is introduced. This kind of coaxial modularized structure not only can be quickly assembled, but also can easily realize different purposes by substituting elements in the system. In addition, it’s light and portable, which enable teachers to carry it to wherever suitable for teaching. In conclusion, this structure can improve teaching effect and stimulate student’s interest in photoelectric courses.
Lecturing is a common approach in the traditional teaching site. In this paper, we bring a modern model “ball game watching theory” to explain the situation in the classroom. The reason why the audiences going to the court is to enjoy the atmosphere, and it is also the reason why student joining to the class. A successful class running is to create studious atmosphere. However, once the teacher does the demo in the class, the multimedia tool must be used to show the details, as the big display working in the court. The key moment is recorded and the details are magnified. when teaching aids are demonstrated, the multimedia tool plays an important role. The attention of students walks between the teacher and the display. In this ball game watching theory, the demonstrate experience is like the ball game, and the teacher works as an anchor. By following the demonstration proceeding, students build the knowledge by themselves. In addition, the demonstration must be designed to be interesting in order to make the class proceed fluently. The similarity between the ball game watching and the class will be discussed. Finally we suggest a modern class design which can raise learner motivation and achievement.
Biology and medicine sample measurement takes an important role in the microscopic optical technology. Optical tweezer has the advantage of accurate capture and non-pollution of the sample. The SPR(surface plasmon resonance) sensor has so many advantages include high sensitivity, fast measurement, less consumption of sample and label-free detection of biological sample that the SPR sensing technique has been used for surface topography, analysis of biochemical and immune, drug screening and environmental monitoring. If they combine, they will play an important role in the biological, chemical and other subjects. The system we propose use the multi-axis cage system, by using the methods of reflection and transmiss ion to improve the space utilization. The SPR system and optical tweezer were builtup and combined in one system. The cage of multi-axis system gives full play to its accuracy, simplicity and flexibility. The size of the system is 20 * 15 * 40 cm<sup>3</sup> and thus the sample can be replaced to switch between the optical tweezers system and the SPR system in the small space. It means that we get the refractive index of the sample and control the particle in the same system. In order to control the revolving stage, get the picture and achieve the data stored automatically, we write a LabVIEW procedure. Then according to the data from the back focal plane calculate the refractive index of the sample. By changing the slide we can trap the particle as optical tweezer, which makes us measurement and trap the sample at the same time.
In this work, we use the liquid-prism SPR sensing configuration to determine the chromatic dispersion of different liquids, since the condition of SPR is sensitive to the refractive index of the liquid prism. We use the glass slide coated with 50 nm Au film as the sensing chip, and use AvaLight - HAL (360 nm - 2500 nm) light source as the broaden band light source in our experiments. We adopt the deionized water as the standard sample to determine the chromatic dispersion of different liquid samples (ethanol and n-hexane), and we implement the experiment through the SPR sensing configuration in angular and spectral interrogations. According to the experimental data, the chromatic dispersions of ethanol and n-hexane are obtained. The proposed technique provides a new high sensitive method for the determination of chromatic dispersion of liquids.