Guided by the shift of the teaching focus to students, the physics optics curriculum has implemented a student-centered teaching innovation, creating an immersive and exploratory case study teaching mode that integrates virtual and real elements. This article focuses on the polarization of light and uses the working principle of polarized glasses in 3D movies as a case study to explore the polarization types, rotation directions, and polarization detection directions of left and right eye lenses. This exploratory case study teaching mode encourages students to discover and analyze problems from life phenomena, design solutions and solve problems with the help of virtual simulation and experimental platforms, enhance practical abilities and innovative thinking through independent exploration, which effectively supports the teaching innovation.

The course of physical optics is committed to promoting a learning-centered teaching model through the transformation of teaching subjects. This paper designs and implements a basic linear polarization optical scene renderer based on path tracing and ray tracing algorithms, which carries out high-precision simulation of the propagation and interaction of polarized light in the scene and generates dynamic visual effects of the polarized light field. The study verifies the simulation accuracy of the renderer for the Fresnel reflection of polarized light at different angles of incidence by means of "virtual-real combination" of experiments and rendering, effectively improving students' understanding and application ability of polarization optics theory. This research provides new tools with quantitative verification functions and visual support for the teaching experiments of Physical Optics and Optical Principles courses, which is helpful to promote the digital transformation of optical teaching.

This paper introduces a student-learning-centered teaching innovation which is basing on the NuSEP simulation imitation platform through research-based project design and immersive experimental exploration. Taking the Michelson interferometer-based absolute gravimeter as an example, we demonstrate the working principle, measurement method and calculation process of the Michelson interference absolute gravimeter by utilizing the NuSEP virtual simulation platform, which effectively addresses the limitations of traditional classroom and laboratory teaching in terms of space, equipment availability, and time constraints. It has enabled any student to conduct experiments at any time and from any place. This platform effectively supports the teaching innovations of the national first-class undergraduate course “Physical Optics” and the graduate elite course “Principles of Optics” in our university.

A bias-independent inter-modulation method is proposed and demonstrated for measuring low-frequency modulation and bias half-wave voltages of Mach-Zehnder modulators (MZMs). The method consists of simultaneous sinusoidal modulation on the modulation and bias ports of the MZM under test. Sinusoidal-modulated sidebands heterodyne with each other and generate the desired inter-modulation products after photodetection, which allows extracting both the modulation depth and half-wave voltage for the modulation and bias ports of the MZM. Our method is independent of bias voltages of the MZM, which can be canceled out by carefully choosing the sinusoidal-modulation frequencies. Moreover, the proposed method enables the low swing voltage for measuring both the modulation depth and half-wave voltage of MZMs. Experiments indicate that the proposed method features the simple setup and high accuracy for low-frequency response measurement ranging from 1Hz to 1MHz.