dc.description.abstract | Laser technology has been widely implemented into many fields, such as light communication, bio-medicine, display technology, remote sensing, environmental detection. Compact, multi-functional yet efficient optical devices are desired in many photonics and laser systems and applications. In this dissertation, those requirements can be potentially fulfilled by introduced one-dimensional (1D) or two-dimensional (2D) periodic or aperiodic photonic devices with the high integration of the electro-optical (EO) modulation, the nonlinear wavelength conversion, and the laser gain medium doping.
In the very first two chapters, the research motivation and background will be introduced, and the theories of the electro-optic effect of lithium niobate crystal will be basically discussed. In the chapter three, 2D nonlinear phtonic devices are demonstrated to perform laser Q-switch as well as optical parametric gain medium (OPGM) simultaneously. Continuous wavelength tuning of the IOPO signal in the eye-safe region via the temperature control of the 2D PPLN and 2D Nd:MgO:PPLN were also achieved. The introduction and description of the desired active laser devices designed by aperiodic optic superlattice (AOS) and optimized by simulated annealing (SA) method will follow. The 1D-/ 2D-NPC based on the developed algorithm with multiple functionalities, including EO Q-switch, EO polarization mode converter (PMC), intracavity second-harmonic generator (ISHG), intracavity sum frequency generator (ISFG), intracavity optical parametric oscillator (IOPO), for variety applications are be reported.
In the chapter four, we demonstrate an electro-optically spectrum tailorable IOPO basked on a novel APPLN device working simultaneously as an multi- wavelength OPDC and an EO PMC (an active wavelength filter) in a diode-pumped Nd:YVO$_4$ laser. A calculation model has been developed to construct the domain structure of the APPLN and to predict the output spectrum of the built EOST IOPO. The measured output signal spectrum of the EOST IOPO producing two narrowed spectral peaks when operated at E$_y$= 150 V/mm at a diode pump power of 4.7 W. Both spectral bandwidths of the two signals were below 0.06 nm (which reaches the resolution limit of the OSA). According to the simulation, not only the signal spectrum but also the idler spectrum can be electro-optically tailored, leading the system to generate narrowed multiple signals and idlers at near- and mid-IR regions, respectively.
Other than forming a spatial structure by the conventional 1D or 2D grating, in the fifth chapter, we design and construct a unique horn-shaped-fan-out-double-prism domain (or ramped duty-cycle) PPLN crystal that integrates the functionalities of an EO beam deflector and an OPDC to work in a compact diode-pumped, 1064-nm Nd:YVO$_4$ laser to realize an efficient EO tunable pulsed IOPG/IOPO. The horn-shaped-fan-out-DPD PPLN crystal can work as an EO beam deflector with a normalized deflection sensitivity of 0.36$^o$/kV-cm and can simultaneously work as a QPM wavelength converter for performing the 1064 nm pumped optical parametric down converter in a range of 1863 - 1929 (by applying -750 V to 750 V). The signal wavelength tuning of the IOPG/IOPO via the electric-field control of the horn-shaped-fan-out-DPD PPLN could be demonstrated in the Mid-IR band. | en_US |