15:30 〜 15:45
▼ [13p-C301-6] Monocrystalline Silicon Microsphere Fabricated by Optical Vortex Laser Illumination
キーワード：Silicon Microspheres, Laser Material Processing, Optical Vortex
Monocrystalline silicon, known as a base material in electronic industry, has been widely investigated in a variety of fields of photonics. In particular, the monocrystalline silicon microspheres will play an important role as whispering gallery mode micro-lasers. Several methods to fabricate microspheres, such as chemical vapor decomposition and laser ablation, have been demonstrated, so far. The aforementioned methods enable the fabrication of the porous, polycrystalline microspheres, however, they are difficult to produce monocrystalline microspheres.
Optical vortex carries an annular intensity profile and orbital angular momentum associated with helical wavefront. To date, we discovered that a single picosecond optical vortex pulse twists the silicon to establish a monocrystalline silicon needle together with monocrystalline micro-sized silicon spheres by orbital angular momentum transfer effects. The fabricated microspheres with relatively high spherecity exhibited a diameter of ~3μm with a standard error of 0.6 mm. The mechanism of the silicon spheres formation is as follows; The melted silicon by optical vortex pulse irradiation receives the forward optical scattering force, so as to direct toward the dark core of the optical vortex to form a monocrystalline silicon needle. After that, the silicon droplets fly away from the tip of the silicon needle and super-cooled to establish the silicon microspheres.
Such monocrystalline silicon microspheres fabricated by optical vortex laser illumination will enable us to provide advanced photonic devices such as whispering gallery mode micro-lasers at high time and cost efficiencies.
Optical vortex carries an annular intensity profile and orbital angular momentum associated with helical wavefront. To date, we discovered that a single picosecond optical vortex pulse twists the silicon to establish a monocrystalline silicon needle together with monocrystalline micro-sized silicon spheres by orbital angular momentum transfer effects. The fabricated microspheres with relatively high spherecity exhibited a diameter of ~3μm with a standard error of 0.6 mm. The mechanism of the silicon spheres formation is as follows; The melted silicon by optical vortex pulse irradiation receives the forward optical scattering force, so as to direct toward the dark core of the optical vortex to form a monocrystalline silicon needle. After that, the silicon droplets fly away from the tip of the silicon needle and super-cooled to establish the silicon microspheres.
Such monocrystalline silicon microspheres fabricated by optical vortex laser illumination will enable us to provide advanced photonic devices such as whispering gallery mode micro-lasers at high time and cost efficiencies.