Abstract: A lens position determination apparatus of an optical pickup includes a lens holder with a mounted lens, a base supporting the lens holder, and a pressing member. The base has an accommodation surface accommodating the lens holder and a pair of facing support walls on the accommodation surface. The pressing member is a bendable arm. A first elastic portion between arm end portions applies an elastic force in a direction in which the arm end portions closely contact the support walls. A second elastic portion connected to the arm presses the lens holder toward the accommodation surface to fix the lens holder position. The lens adjustment can be performed while the pressing force to fix the lens holder to the base is removed by bending the pressing member into a V shape to reduce frictional resistance of the lens holder with the base during the adjustment.

Abstract: An optical pickup condenses a light emitted from a light source using an objective lens and irradiates the light on an optical recording medium to record data on the optical recording medium and/or to reproduce the data recorded on the optical recording medium. The optical pickup includes an optical element adjusting a convergence and/or a divergence of the light emitted from the light source and proceeded to the objective lens.

Abstract: An optical pickup to focus a light emitted from a light source using an objective lens, forming a light spot on a recording surface of a recording medium, and performing recording and/or reproducing operations using the light. The optical pickup includes a monitor photodetector and an optical element installed in front of the monitor photodetector to receive and to detect a portion of the light emitted from the light source to control an amount of light power output from the light source and to adjust at least one of an intensity, a beam profile, and a proceeding direction of the light incident on the monitor photodetector.

Abstract: A harmonic wave generator including a light source to generate a fundamental wave having a predetermined wavelength, a non-linear material to transform at least a portion of the fundamental wave generated by the light source into a harmonic wave having a shorter wavelength than the fundamental wave, and a first optical device to separate the harmonic wave generated by the non-linear material from the fundamental wave. The harmonic wave generator further includes a second optical device between the condensing lens and the non-linear material to adjust the depth of the focus of light. The harmonic wave generator is easily assembled and can be manufactured at a low cost. A harmonic wave having high power can be generated.