A heterodyne interference lithography method using two slightly different wavelengths for one-step multi-scale fabrication of micro/nano hybrid structures is presented. This method has been used to locally fabricate one- and two-dimensional periodical sub-wavelength nanopatterns with a spatial periodicity of several micrometers. Furthermore, multilayered nanostructures with different layer compositions were fabricated by simply controlling the intensity ratio of the two wavelengths. As a result, this method can cost-effectively maximize the degree of freedom of the interference lithography method. The heterodyne interference lithography method can potentially be used in the fabrication of unconventional bio-mimetically engineered surfaces as well as heterocomplexed optics.

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An overview on femtosecond laser pulse shaping techniques applied to control of the initial photo-physical steps involved in materials processing is presented. First, pulse shaping methodology in frequency domain is introduced and examples of shaped pulses relevant to laser microfabrication are discussed. Then, the use of tailored femtosecond pulses to control the initial steps of laser processing of high band gap materials is demonstrated. In particular, control on basic ionization processes acting as the initial photo-physical step of the ablation dynamics is exerted by highly asymmetric femtosecond laser pulse shapes generated by Third Order Dispersion (TOD).

A multi-stage gear mold including gears of 2mm and 1.5mm diameter was designed and machined in this research for developing micro gear mold manufacturing technology with micro endmill. Mechanical shapes having differential micro teeth were analyzed to be formed as designed and processing conditions were optimized by analyzing machined surface chip and cutting force. Based on the results, a prototype of micro multi-stage gear mold was manufactured.

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