Laser fabrication of 1D and 2D periodic subwavelength gratings on titanium films

The nanogratings of controllable topography are in a great demand in optics, photonics, and sensing, although their fast, flexible, and large scale fabrication could be a challenge for lithography and other modern methods. In this article we offer a simple method of creation the patterned coatings based on the direct laser-driven creation of periodical surface structures on thin titanium films. By controlling the laser polarization, 1D and 2D square and honeycomb patterns of a fully manageable topography were created on Ti film deposited onto glass substrate under cross-scanning irradiation by nanosecond near-IR laser pulses. Comprehensive study was conducted on the formation mechanisms, internal structure, and optical properties of 1D and 2D gratings. The article also discusses the optical properties of the gratings, demonstrating that various optical effects can be obtained by controlling the orientation angles of the gratings. A polarizing filter prototype was generated by dynamically controlling the laser polarization. The resulting patterns have high repeatability and controllable optical properties, making them suitable for various applications including photonics, polarization optics, and security labeling.