Fabrication of out-of-plane SU-8 refractive microlens using direct lithography method

To develop an integrated optical bench or free-space optical system, a focusing lens’ optical axis is required to be parallel with the substrate on which the whole system is located. In micro-optical systems, hinged lenses were fabricated in surface technologies and suspended with a mechanical hinge, then driven up to the required vertical position using electrostatic or electromagnetic actuation. In this paper, we report the research work to design, simulate, and fabricate a new type of microlens using direct lithograph of SU-8 resist. Without any assembly process, this microlens’ optical axis is parallel with the substrate on which the whole optical system is. The lenses obtained this way are perpendicular to the substrate and can be pre-aligned with other micro optical components. The focus of the lens can be controlled with different surface curvature by using different cylindrical beams, expose dosage, and development time. A numerical simulation is done about the SU-8 development. The optical simulation is also being done with ZEMAX software. At the same time, the optical properties of the cured SU-8 and the optical properties of this cured-SU-8 refractive microlens are also being tested and presented in this symposium.