Yoshida's research focuses on circularly polarized luminescence (CPL), which has been gaining a great deal of attention in the field of optics in recent years. CPL is expected to be used not only as a light source for 3D displays, but also in optical telecommunications technology, advanced security printing, plant growth promotion, and many other fields.
　CPL refers to light that travels in a leftward or rightward spiral. In the case of 3D movie screenings in theaters, glasses (polarizing lenses) are used to show separate images to the left and right eyes by shifting transmitted light to the left or right according to the direction in which the light rotates, thus creating the sensory illusion of three-dimensional images. Conventional circular polarization is produced by converting the light with a circular polarizer (a type of filter), but it is extremely difficult to reduce the brightness caused by the filter and to miniaturize the equipment. This led to the idea of generating CPL without the need for a filter. However, current CPL materials have issues with luminous intensity (i.e., circular polarization and brightness) among other things, and researchers have not yet reached the stage where these materials can be practically applied.

　In his research, Yoshida is trying to control the structure at various levels of hierarchy, from the microscopic molecular level to the macroscopic material level, in order to improve the luminous intensity of CPL materials to the utmost limit. If new organic CPL materials can be developed, this would be a major step toward practical application.
　What’s more, there are considerable preparation costs involved in the development of innovative organic CPL materials. Therefore, the efficient preparation of these materials is a critical research topic.
　“For example, during endoscopic surgery, doctors currently look at a two-dimensional screen, but if they could view the screen in three dimensions, they would be able to perform the procedure with greater precision. Also, when robots work in hazardous areas, if the operators could control them on a three-dimensional screen, they could operate the robots more accurately from a safe location. Once 3D displays are realized, I think we will see significant progress in a wide variety of fields," says Yoshida.

　Yoshida’s first encounter with organic CPL materials research was after he joined the graduate school when a large-scale project called Creation of Innovative Basic Technologies for Circularly Polarized Luminescence Materials Development—a project that aims to create fundamental technologies related to CPL— was adopted by the Japan Science and Technology Agency (JST) under the Core Research for Evolutional Science and Technology (CREST) program. This project brings together researchers from several universities to conduct collaborative research.
　“At first, I was assigned to Professor Tomonori Hanazaki's laboratory at the Graduate School of Life Sciences, but when the project leader, Professor Kazuo Akagi, came to Ritsumeikan University, I decided to work with him on the project while pursuing my own research. It was truly an invaluable experience to be able to work with Professor Akagi, who is a pioneer in CPL research," said Yoshida. To balance his work on this large project with his own research, Yoshida devoted every waking hour to research. After that, he decided to enter the doctoral program because he wanted to acquire a wide range of skills by experiencing things that can only be experienced in the doctoral program while working toward his goal of landing a corporate R&D position.

　As a student in the doctoral program, Yoshida is now in a position to supervise younger students. He says this experience has helped him grow significantly. “In addition to developing teamwork skills, it is essential for each researcher to improve their own competencies. For this reason, I am always conscious of what kind of guidance is appropriate for improving an individual researcher’s competencies. Also, since many people are involved in the project, I must build relationships and be mindful of creating a better environment for the team to conduct research. I feel that these experiences have helped me grow a great deal in terms of my human skills, including management skills, logical thinking, and leadership skills. The ability to enhance these abilities is a great asset of the doctoral program. For the remainder of my research life, I hope to grow more in terms of these human skills in addition to further developing my expertise," said Yoshida.
　Yoshida has been chosen as a Ritsumeikan University NEXT Student Fellow. Ritsumeikan University selects promising, highly motivated doctoral program students to serve as Ritsumeikan University NEXT Student Fellows, and it is implementing a program to help these fellows deepen their expertise and acquire a broad range of research perspectives while working with talented researchers who are conducting cutting-edge research in a diverse array of fields.
　He described the significance of the program as follows: “It really helps that the university is providing me with career support. Because I am so busy with my own research and the project, I have limited time to devote to job hunting. I am grateful for this support, which is both caring and specific to the doctoral program."
　After completing his doctoral studies, Yoshida aims to secure a research and development position in the private sector. We hope that he will use the expertise and human skills he has acquired from managing his research projects to create products that will revolutionize society in the near future.