Transmission Properties Of THz Radiation Pulses Through Very Deep Zero-order Metallic Gratings With Subwavelength Slits

Terahertz time-domain spectrometry (THz-TDS) is an effective phase-coherent photometric method by which one can directly measure the time-resolved electric-field, including both amplitude and phase of a nearly single-cycle subpicosecond THz radiation pulse generated by the mode-locked femtosecond pulse laser, and the THz-TDS may become an effective technique for characterizing the transmission properties through various microstructured devices at THz frequencies. In this dissertation, we presented a primary experimental study on transmission properties of THz radiation pulses through very deep zero-order metallic gratings using our homemade THz-TDS. For the first time, the enhanced transmission due to surface plasmon-polaritons (SPPs) was abserved. At the same time, we theoretically analyze and numerically simulate the transmission properties of THz radiation pulses through very deep zero-order metallic gratings.The main contents of this dissertation are classified as follows:In Chapter One, we mainly introduce the backgrounds and significance of the dissertation.The most recent study results of terahertz radiation surch as theTHz generation, detection, characters, applications, are reviewed in Chapter Two.The basic physics characters of surface plasmon polaritions(SPPs) and its coupling device are described in Chapter Three.We theoretically study the transmission properties of THz radiation pulses through very deep zero-order metallic gratings, and numerically simulate and analyze the dependences of the transmission spectra on frequency in Chapter Four.In Chapter Five, the experimental results are discussesed on ground of the theory studied in the previous chapters.