Electromagnetic modelling of the optical properties of Spatial Light Modulators

The spatial light modulator (SLM), especially liquid crystal on silicon (LCoS) type has multiple applications in optical systems, such as beam steering, beam shaping or computational holography. At the same time, there are many factors need to be examined carefully when using LCoS, like pixilation, phase fluctuation, temperature effect. These effects will influence the optical property when LCoS is used as diffractive optical elements. To predict and improve the diffraction efficiency, further robust electromagnetic simulation, including FDTD, FEM or RCWA, is needed. Then, with the help of experiments, we expected to verify the simulation results and find better methods to improve these effects when applying on different optical systems.

---

Objective

In this project, we aim to accurately characterize the optical loss from the backplane of LCoS SLM with experiment and simulation. Then, develop a proper electromagnetic modeling method to simulate the near field of the LCoS SLM within a reasonable time. Finally, based on these researches, optimize the optical performance of the LCoS SLM concerning different applications.

---

Impact

With the accurate characterization of the optical loss from the backplane of LCoS SLM, we can tailor the optical design of the backplane for different applications to enhance the reflectivity while minimizing the fringing field effect. The suitable electromagnetic modeling method for LCoS SLM help identify the possible optical loss for different design parameters in phase-related applications.

---

Publications

• Finite element method for 3D optical modeling of liquid crystal on silicon spatial light modulator (Oral presentation)

  Po-Ju Chen, Philip Engel, Clement Abelard, Adam Mazur, and H. Paul Urbach, Emerging Liquid Crystal Technologies XV, SPIE Photonics West (2020)

• Design, implementation and study of the high-resolution high-efficiency liquid crystal on Silicon spatial light modulator for the telecommunication application in the short wave infrared spectral band (Oral presentation)

  Po-Ju Chen, Philip Engel, Grigory Lazarev, Adam Mazur, and H. Paul Urbach, Emerging Liquid Crystal Technologies XIV, SPIE Photonics West (2019)

• Beyond the display: phase-only liquid crystal on Silicon devices and their applications in photonics [Invited]

  Grigory Lazarev, Po-Ju Chen, Johannes Strauss, Nicolas Fontaine, and Andrew Forbes, Opt. Express 27, 16206-16249 (2019)