Abstract: Provided is a microelectromechanical system (MEMS) actuator in which a cantilever piezoelectric actuator and a comb actuator are combined to perform dual shaft drive. The MEMS includes: a stationary comb fixed on a substrate; a movable comb disposed separately from the substrate; and a spring connected to the movable comb and the substrate to resiliently support the movable comb, wherein the movable comb includes a piezoelectric material layer in a laminated manner to be perpendicularly moved by a piezoelectric phenomenon and laterally moved by an electrostatic force to the stationary comb, whereby the MEMS actuator can be used in a driving apparatus of an ultra-slim optical disk drive since the movable comb is made of a piezoelectric material to simultaneously perform focusing actuation to a Z-axis as well as planar actuation.

Abstract: Provided are an optical fiber that prevents optical amplification bands from overlapping each other while enabling optical signal amplification by a rare-earth element and optical signal amplification by a nonlinear Raman effect to simultaneously occur by performing a pumping operation using a single-wavelength light source, and a hybrid optical amplifier using the same. The optical fiber includes: a clad; and a core configured to have a refractive index larger than that of the clad, the core including a first element doped to receive pumped light having a predetermined wavelength and optically amplify the received signal light into a first band using a rare-earth element, and a second element doped to optically amplify the received signal light using nonlinear Raman optical amplification into a second band.

Abstract: Provided is a method of manufacturing a thin film magnetic head.