2.1

Motivate study interest to Optics

Interest is the motive power of education. While, how to keep the interest of the students? We try to supply many opportunities in different aspects. Firstly, practical training for students is added before the study of professional course in recent years. Students have the chance to visit some company engaged in optical instruments. They are allowed to look around the production line of several companies such as Beijing Beifen-Ruili Analytical Instrument (Group) Co. Ltd. This is helpful for the students to know the applications of the optical technique in the larger sense. During the process of invitation, students usually ask many questions related with technique, and some issues are exactly the problem that the faculty of company is trying to solve. Actually, many problems will be settled with the development of scientific technique, which make students investigate that there are many things to do and increase the motivation of study.

The demonstration hall has exhibited many principle prototypes or interesting optical experimental phenomenons in our college, which includes michelson interferometer, resolution of imaging system, the spectrum of grating etc.. These optical phenomenons can raise the interests of students, and help students to deeply comprehend the optical theories introduced in class. Furthermore, there are three correlative research laboratories composed by information optics laboratory, micro-nano optics laboratory and optical fiber communication laboratory in our university. Students are invited to visit these laboratories. During the invitation, students can fully aware the status of the optics researches, and they can know or operate the common optical components.

Besides, the basic optical theory is generally explained as the teaching content in class. The related applications or instruments, especially the research frontiers in optics, are introduced in class, and these usually attract the attention of students and broaden their view. Of course, this kind of class demands that the teachers should have experience of research about optics and be able to keep up with the development of optical technology. All of these work try to make students investigate the actual applications and developments of optics technology, and know the frontier of scientific research.

2.2

Digital simulation and experimental design by students

Supposing that the incident light is a simple harmonic wave, most of the interference and diffraction theories can be simulated by software such as Matlab or Excel. The simulated results can help them comprehend the meaning of some difficult theories. For example, the nature of Thomas Young dual-slit interference experiment is the interference of two spherical lights. In the 3D space, the interference patterns of two spherical lights S₁, S₂ are different for the screen m in different directions. Some students cannot understand this. According to the optical path difference Δ = r₂ – r₁, the interference pattern is a cluster of two-sheeted hyperboloid of revolution with the focus points S₁, S₂ [6], and the simulated results are shown in Fig. 1. The 3D optical field for the constructiue interference is described in Fig. 1 (a). Figure 1(b-d) are the interference patterns respectively when detecting on the planes parallel to y-z plane, x-y plane and a tilted plane. With the help of the simulated stereo image, students can observe the interference pattern intuitively.

Figure 1.

(a) 3D optical field for the constructiue interference. (b) Interference pattern when detecting on a plane parallel to y-z plane. (c) Interference pattern on a plane parallel to x-y plane. (d) Interference pattern when detecting by a tilted plane.

Simulation results for the interference of two spherical lights.

Besides, some demonstrations are proposed and designed by students. For instance, a demonstration apparatus for the measurement of Brewster angle is produced this year. In the demonstration apparatus, a laser pen is used as light source, an optical glass is utilized as the reflection interface, and a dial scale carved by laser is applied to confirm the angle directly. Not only the Brewster law can be demonstrated by the apparatus, but also the Fresnel formula can be proved quantitatively in the combination with polarizing beam splitter (PBS) and optical power meter. The practical teaching demonstration indicates that the apparatus can effectively assist students understanding the relationship between the incident light power and reflected light power in the interface of isotropic mediums, which can motivate the studying enthusiasm of students with a good teaching effect. Though the principle and the structure of the demonstration apparatus is simple, the design process can ensure that students can understand the theory clearly and further improve their practical ability.

2.3

Help students achieve their ideas

During the study of the optics course, students may have some interesting ideas in combination of practical applications. For one thing, students need the guidance of teachers; for another, they don’t have enough money to achieve their minds. Considering this case, our university and teachers can help them if their ideas are of significance. Students can apply for the Plan of Talent Students or Starfire Fund from university. There will be some money to buy the necessary elements, and teachers can discuss with students and give a feasible scheme. Meanwhile, students try to achieve the targets under the guidance of teachers. Since the principles of the microscope and telescope are introduced in the class, many students would like to design the structure of some imaging systems. For example, one of our students is interested in the optimization of car light. He used the software Tracepro to simulate and calculate the parameters of LED light, and then made the light. The performance is improved by optimization of LED. Once the students have this experience, they will be brave to propose their ideas, and know the basic steps to realize their target. All of these are helpful for their subsequent work or study.

2.4

Invite talent students to join special research groups

The capability of students is different, and some talent students have free time and would like to do some special research. Especially, the students supported by the funds of university have the stronger motivation to enter a laboratory earlier. Meanwhile, teachers usually have some national or city level funds, and would like to invite talent students to join their research groups. In our group, we have a scientific seminar per week, and students are also invited to join it. These students have the chance to discuss with the graduate students and teachers. During the discussion, they can learn how to search the related references and how to give the feasible plan. After the decision of the research plan, they have the opportunity to do experiments in the laboratory under the guidance of teachers. They can revise the experimental scheme continually. Some students may achieve their targets, but not all of students can be satisfied with the results. However, the process is more important than the result.

It is useful for students to join the research group. For one thing, students can combine the theory with experiments, and apply the basic knowledge to settle the practical problem and optimize the scheme. In the laboratory, students can be familiar with many optical instruments and learn to operate them. All of these can improve their analytical and manipulative ability. For another, undergraduates are also a good supplement to our group. These students are young and active. Though they lack of some experience, they can also supply some new and simple methods to solve the problems. Furthermore, students can improve their cooperation ability during the discussion with the graduate students and teachers.