Femtosecond Laser Processing Integrated Airy Phase Plate And Research On Its Diffraction

Airy beams have stimulated considerable interests in the fields of microscopy,optical manipulation,plasma channels and nonlinear photonics owing to its intriguing properties including retaining diffraction-free over a long distance,self-healing and quadratic transverse acceleration during propagation.Utilizing the property of the frequency spectrum of Airy function,Airy beam can be generated by Fourier transforming a Gaussian beam in which a cubic phase factor is encoded.While in the field of micro-optics,conventional optical elements used to modulate the wavefront of the Gaussian beams suffer from their centimeter-scale dimensions,and a bulky Fourier lens used to perform the Fourier transformation further improves the difficulty of the integration of the optical systems.In this thesis,we propose the design and fabrication of miniature(60 ?m×60 ?m×1.1?m)Airy phase plates.In addition,a phase-type Fresnel zone plate(FZP)is incorporated in the phase plate,which makes the integrated Airy phase plate(IAPP)directly generate Airy beams at the corresponding Fourier plane.The IAPPs are fabricated by the high precision femtosecond direct laser writing(FsDLW)technique.The main contents are as follows:1.Based on the Fresnel diffraction theory,we derive the optical field of the Airy beams generated by the phase plate in which a cubic phase as well as a phase-type FZP is encoded.The phase distribution of the IAPP is demonstrated by a computer-generated-hologram and the height information of the corresponding phase plate is obtained.2.Then we realize the fabrication of the IAPP based on the galvomirrors system.The high processing quality of the fabricated IAPP is verified experimentally,which guarantees the generation of the high-quality Airy beams.Then based on the high flexibility of the FsDLW,the designed IAPP is integrated successfully onto an optical fiber facet,which further demonstrates the high level of integration of our designed IAPP.3.Finally,the diffraction optical field of the IAPP fabricated on a cover glass is researched.The Airy beam is generated by irradiating the IAPP with a continuous-wave laser beam(532 nm),and the intensity distributions of the Airy beam are recorded by a CCD camera.The transverse self-accelerating trajectory of the Airy beam is synthesized using the captured images of the Airy beam at different propagation planes,which is in good agreement with the theoretical simulation.The quasi-diffraction-free property and the self-healing property of the generated Airy beam are verified experimentally.Moreover,by altering the focal length of the phase-type FZP,we can change the initial position and the curve trajectory of the Airy beam,which demonstrates the high flexibility of our designed IAPPs.