JPH047502A - Optical element and hologram exposing method - Google Patents

Abstract

PURPOSE:To perform exposure through a hologram lens with small noise by employing a beam splitter which is united with a pinhole. CONSTITUTION:The light emitted by a laser light source 1 is split into two, and one light beam is converged by an objective 4, passed through the pinhole 5, and the diverged light from the pinhole is used as object light 9. The other light beam is made incident on the beam splitter 6, inserted into the optical axis of the object light 9, at right angles to the optical axis and made to interfere with this object light 10. In such a case, the pinhole 5 which is united with the beam splitter 6 is used. Consequently, the pinhole 5 can be positioned at the position where the object light 9 is converged so that the reference light 10 is not cut off. Consequently, diffracted light generated owing to the high-order mode in the laser luminous flux and a dust, etc. on the lens is cut off to enable the interference exposure with small noise.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical element and a method of exposing a hologram lens.

[Prior Art] A conventional hologram lens exposure method uses a diffraction element such as an auxiliary hologram to guide the reference light parallel to the optical axis of the object light, as described in the Institute of Electronics and Communication Engineers Technical Research Report ED80-70. , there was one that recorded the interference fringes of the reference beam and object beam on a dry plate.

[Problems to be solved by the invention] However, the conventional exposure method using an auxiliary hologram has the following problems:
As shown in FIG. 2, the object light 13 is
Since the point where the reference beam 14 converges overlaps with the reference beam 14, there is a problem in that it is difficult to use a spatial filter. Therefore, the present invention is intended to solve these problems, and its purpose is to provide a method of exposing a hologram lens with less noise by employing a beam splitter integrated with a pinhole. be.

[Means for Solving the Problems] The optical element of the present invention is characterized in that a pinhole and a beam splitter are integrated. Further, the hologram exposure method of the present invention is characterized in that an optical system for recording a hologram by interference exposure includes the optical element.

[Function] According to the above configuration of the present invention, the light emitted from the laser light source is split into two, one of the lights is converged by the objective lens, and the light passes through the pinhole, and the light diverging from there is used as the object light. used as

The other light enters a beam splitter inserted on the optical axis of the object light from a direction perpendicular to the optical axis, and is caused to interfere with the upper object light. The present invention uses a pinhole integrated with a beam splitter. Therefore, a pinhole can be placed at a position where the object light converges so as not to block the reference light. By placing a pinhole, it is possible to block higher-order modes in the laser beam and diffracted waves due to lens dust, etc., making it possible to perform interference exposure with less noise.

Hereinafter, the details of the present invention will be shown by examples.

[Example 1] FIG. 1 shows the configuration of an embodiment of the present invention.

Pinhole 5 is 5μ in a 13mm thick stainless steel plate.
It is made by pasting one of the incident surfaces of the beam splitter 6 with a hole of m in diameter, and when passing through the pinhole 5, it is protected against high-order mode light in the laser beam and dust attached to the lens. Unnecessary components such as diffracted light can be removed. As a method of integrating the beam splitter and the pinhole, it is also possible to directly deposit A1 on the beam splitter.

[Example 2] Light emitted from a He-Cd laser 1 having an oscillation wavelength of 441.6 nm is split into two by a half mirror 2. One of the lights is converged on the pinhole 5 by the objective lens 4. The light passing through the pinhole 5 becomes diverging light. The diverging light enters a beam splitter 6 integrated with a pinhole 5 and is split into reflected light and transmitted light. Among these, the light that is transmitted and enters the dry plate is used as object light 9. The other beam split by the half mirror 2 enters the beam splitter 6 from the side. Although the beam splitter 6 separates the reflected light and transmitted light, only the reflected light is used as the reference light 10 here. Interference fringes between the object beam 9 and the reference beam 10 are recorded using a glass substrate 8 coated with a photosensitive material 7. The reference beam 10 is guided to the optical axis of the object beam 9 using a beam splitter 6, and an in-line hologram lens can be manufactured. Further, it is also possible to manufacture a lens that converts divergent light into convergent light by inserting an objective lens into the path of reference light 10 and making the convergent light enter the beam splitter 6.

[Effects of the Invention] As described above, according to the present invention, by integrating the pinhole and beam splitter, the number of elements constituting the optical system can be reduced, and optical axis alignment can be easily performed. It has the effect of becoming.

Further, according to the present invention, by using a pinhole-integrated beam splitter, exposure of a hologram lens with less noise is possible.

It is a diagram.

1 ・ 2 ・ 3・ 4 ・ 5 ・ 6 ・ 7 ・ 8 ・ 9 ・ 10・ 11・ 12・ 13・ 14・ laser half mirror full mirror objective lens Pinhole beam splitter photosensitive material glass substrate object light reference light auxiliary hologram dry plate object light reference light

[Brief explanation of the drawing]

Claims (2)

[Claims] (1) An optical element characterized by an integrated pinhole and beam splitter. (2) A hologram exposure method, characterized in that an optical system for recording a hologram by interference exposure includes the optical element.