Direct writing computer-generated holograms on metal film by an infrared femtosecond laser

Abstract

Writing computer-generated holograms have been achieved by using a near infrared femtosecond laser selective ablation of metal film deposited on glass substrate. The diffraction features with data reconstruction of the fabricated computer-generated holograms were evaluated. Both transmission and reflection holograms can be fabricated in a single process. The process requires no mask, no pre- or post-treatment of the substrate.

Femtosecond off-axis digital holography for monitoring dynamic surface deformation

“…2, we can calculate the phase difference ϕ diff and amplitude changes A change of the Cr film using Eqs. (10) and (11). shows the amplitude and phase change calculated from the holograms shown in Figs.…”

“…In addition, the femtosecond laser offers a unique possibility to study ultrafast phenomena that accompany light-matter interaction. Femtosecond light-matter interaction is attracting increasing interest, both from a fundamental physics viewpoint and with respect to practical applications of ultrashort laser pulses for micromachining technology [8][9][10][11].…”

Holographic Fabrication of Periodic Microstructures by Interfered Femtosecond Laser Pulses

“…Femtosecond laser pulse is also becoming into a powerful tool for microfabrication and micro-machining of various multi-functional structures in dielectric materials through multi-photon absorption because of its high-quality and damage-free processing. Up to now, many highquality material processing techniques have been achieved by using femtosecond laser pulses with the methods of directly writing [1][2][3][4][5][6][7][8][9][10] and holographic fabrication [11][12][13][14][15][16][17][18][19][20][21][22], such as waveguide [1], special diffractive optical elements (DOE) [4][5][6][7][8][9][10], micro-gratings [11][12][13][14][15], and photonic crystals [16][17][18][19][20]. Because multiphoton nonlinear effects play a major role in this process, the resulting change in refractive index or cavity formation can be highly localized only in the focal volume where the fluence is above a certain material dependent threshold, which makes it possible to micro-fabricate devices inside the bulk of transparent materials.…”

Several Diffractive Optical Elements Fabricated by Femtosecond Laser Pulses Writing Directly

“…Many highquality material processing techniques have been achieved to date by using femtosecond laser pulses with the methods of holographic fabrication [1][2][3][4][5][6][7][8] and direct writing [9][10][11][12][13][14][15][16], such as micro-gratings [1][2][3][4], photonic crystals [5][6][7][8], waveguide [9] and diffractive optical elements (DOE) [10][11][12][13][14][15][16]. In this chapter, we have reported to fabricate several diffractive optical elements (DOEs) on the surface of the metal film or inside transparent silica glass by femtosecond laser pulses writing directly.…”

“…Qd n πλ =Λ defined by Kogelnik [11,12,16,40], where Λ is the period of the gratings, d is the thickness of the diffraction grating, n is the refractive index, and λ is the wavelength of the incident beam, we can enlarge the thickness or reduce the period of the diffraction grating for obtaining a larger diffraction efficiency. Because of the self-focusing and self-defocusing effects, there would be a line of self-assembly periodic nanovoids generated spontaneously along the propagation direction of the laser beam, when a femtosecond laser beam is focused into transparent glass with proper pulse energy.…”