JPS62186219A - Semiconductor laser device - Google Patents

Abstract

PURPOSE:To reduce the size of an optical system in an optical disk device and to reduce the number of parts of an optical system for shaping beams by arranging a cylindrical lens in the front of a chip to be a light source correspondingly to an elliptic projection beam as an approximately circular beam to radiate the approximately circular beam. CONSTITUTION:The chip 12 is a light source for a semiconductor laser device 11 and the recessed cylindrical lens 13 has function for shaping an elliptic projection beam projected from the chip 12 as an approximately circular beam in addition to the function of a cover glass. In the semiconductor laser device 11, a small elliptic light beam obtained immediately after being radiated from the chip 12 can be shaped as an approximately circular beam.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to the simplification of the optical system of an optical disk device, and particularly to a semiconductor laser device.

Conventional technology The optical system of an optical disk device basically shapes the elliptical radiation of a semiconductor laser into a substantially circular beam after being emitted from the laser, and focuses the beam onto the disk recording surface to a diameter of 1 μm or less. be. Figure 2 shows the configuration of a conventional optical system that shapes an elliptical synchrotron beam into a substantially circular shape. 1 is a semiconductor laser device, which protects a chip (not shown) as a light source and a collimating lens. It has a cover glass (not shown) which functions as an optical component for the purpose of correcting aberrations until the light enters the light beam. The elliptically emitted light from the semiconductor laser device 1 is condensed into elliptically parallel light by a collimating lens 2, and then, as shown in FIG. In FIG. 2(b), the beam is shaped into substantially parallel beams by a shaping prism 5. Thereafter, the beam is shaped into substantially parallel light beams and is passed through an objective lens (not shown) to the disk recording surface (not shown).
The light is focused on the top. Although the number of shaping prisms 5 is one in FIG. 2(b), a combination of 2flX1 may be used.

Problems to be Solved by the Invention In the conventional shaped beam type optical system, ■ At the stage of converting elliptical radiation into substantially parallel beams, the luminous flux already has a diameter of φ5 to 6.
μm, and the corresponding lens or prism is large enough to cover this, and the optical block after completion tends to be large.■ When shaping with a cylindrical lens, concave and convex combination is required, and the number of parts including the lens holder tends to increase. ■ When shaping with a prism, the Brewster angle is often used, so the entire optical block has an irregular structure due to the angle of incidence. The problem was that it was easy to do so.

The present invention solves the above problems, and aims to provide a semiconductor laser device that can miniaturize the optical system in an optical disk device and further reduce the number of parts of the shaped beam optical system. It is something to do.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a semiconductor laser device in which a semiconductor laser device is provided with a structure in which the front surface of a chip serving as a light source corresponds to the X-axis and Y-axis of the elliptical emitted light emitted from the chip. A cylindrical lens is installed to shape the elliptical emitted light into a substantially circular shape and radiate it.

Effect With the above configuration, the elliptical emitted light from the chip that is the light source can be shaped into a substantially circular beam within the semiconductor laser device when the beam diameter is small, eliminating the need for conventional optical components for beam shaping. can do.

Example An embodiment of the present invention will be described based on the drawings.

FIG. 1(a) shows a cross section of a semiconductor laser device according to the present invention, and FIG. 1(b) shows a cylindrical lens attached to the emission surface of the semiconductor laser device. 11 is a semiconductor laser device, and 12 is a chip that is a light source of the semiconductor laser device 11. 13 is a concave cylindrical lens which, in addition to the function of a cover glass, has an additional function of shaping the elliptical output light from the chip 12 into a substantially circular shape;
It replaces the conventional cover glass.

According to this semiconductor laser device 11, the elliptical emitted light can be beam-shaped into a substantially circular shape at a point in time when the luminous flux is small immediately after the light emission from the chip 12 within the device.

In addition to the effects of the invention, according to the present invention, since beam shaping is performed within the semiconductor laser device, conventional optical components for beam shaping are not required, and the entire optical block can be downsized and cost reduced. Great value.

[Brief explanation of drawings]

FIG. 1(a) is a cross-sectional view of a semiconductor laser device showing an embodiment of the present invention, FIG. 1(b) is a perspective view of a cylindrical lens, and FIGS. 2(a) and (b) are elliptical radiation FIG. 2 is a configuration diagram of an optical system that beam-shapes light into a substantially circular shape. 11... Semiconductor laser, 12... Chip, 13.
・・Concave cylindrical lens representative Yoshi Morimoto Arc part 1 Figure 1f-11 ↑ Zeni 1ζshi-"Lee-11 12-Natsutsu 0

Claims (1)

[Claims] 1. A cylindrical lens is installed on the front surface of the chip as a light source, corresponding to the X-axis and Y-axis of the elliptical output light emitted from the chip, so that the elliptical output light is shaped into a substantially circular shape and then radiated. semiconductor laser device.