Fig. 1. Schematic diagram of tilted-pulse-front terahertz radiation device. (a) Traditional structure based on separated grating; (b) oblique-incidence contact grating structure; (c) collinear radiation structure based on contact grating

Fig. 2. S polarization incidence scheme and pump electric field intensity distribution diagram. (a) Schematic diagram of grating structure and polarization of pump pulse; (b) pump light electric field intensity distribution

Fig. 3. Parameterized scanning results of grating optimization, and two curves completely overlap due to the symmetry of the ± 1st order diffraction order. (a) Curves of diffraction efficiency of silicon grating with duty cycle; (b) curves of diffraction efficiency of silicon grating with grating height variation; (c) curves of diffraction efficiency of LN grating with duty cycle; (d) curves of diffraction efficiency of LN grating with grating height variation

Fig. 4. Numerical simulation results. (a) Simulated tilted-pulse-front terahertz radiation spectrum (2 mm away from the front surface of crystal); (b) simulated variation trend of electric field intensity of terahertz wave at 1 THz frequency with propagation distance in z direction; (c) simulated variation trend of time-domain terahertz radiation peak intensity with propagation distance in z direction