JPH0273213A - Composite optical parts - Google Patents

Abstract

PURPOSE:To miniaturize a composite optical parts by placing said parts so that an optical element of one side rotates by a prescribed angle around an optical axis in a state that the optical axes for intersecting an optical function film of a first optical element and an optical function film of a second optical element at an equal prescribed angle, respectively, are allowed to conform with each other. CONSTITUTION:A laser light L (P wave) emitted from a laser light source 1 is separated into a partial laser light L1 which is made incident on a first optical element 24, reflected by a first optical function film 22 and emitted in the direction of a monitor (not shown in the figure), and the greater part of laser light L2 which transmits through the optical function film 22 and emitted from an optical element 23 as it is. Also, the laser light L2 passes through an objective lens 8 and irradiates a prescribed position of a recording medium 9, and a laser light L3 on which an irradiation light P wave reflected from the recording medium 9 and a signal wave S wave are superposed goes to a laser light L4 after a part of the P wave and the whole of the S wave are reflected by the optical function film 22, and made incident on the optical element 24. Subsequently, laser light beams L5, L6 on which a P wave component and an S wave component which are allowed to transmit and reflected by an optical function film 25 of the optical element 24 and emitted from the optical element 24 are superposed, and detected by photodetectors 27, 28 provided on its optical path, and a difference of measured values is detected and information data can be obtained as the recording medium 9.

Description

[Detailed Description of the Invention] [Summary] Regarding composite optical components incorporated in optical signal circuit networks, the present invention aims to reduce costs and improve productivity by integrating multiple components to reduce size and assembly/adjustment man-hours. For the purpose of In the same way, one optical element is rotated by a predetermined angle around the optical axis with the optical axes that intersect the optical functional film of the optical element and the optical functional film of the second optical element at the same predetermined angle aligned with each other. Place and configure.

[Industrial application field]

The present invention relates to an optical device incorporated into an optical signal circuit network, and more particularly to a composite optical component that is smaller in size and lower in price by reducing the number of components.

In general, optical devices that use optical signals, such as magneto-optical disk heads, use a laser beam as a light source, and when the laser beam is irradiated onto a recording medium, the optical signal reflected from the medium is transferred to a beam splitter or a wavelength plate. Methods have been used to efficiently obtain optical signals from a medium by separating them through a medium or rotating the plane of polarization.

[Conventional technology]

FIG. 3 is a principle diagram showing an example of the configuration of a conventional optical device, where (A) is a perspective view of the configuration and (B) is a side view.

In Figures (A) and (B), ■ is a laser light source such as a laser diode, and the first optical component 2 is composed of two optical prisms 3 of equal size and having a cross section of a right isosceles triangle.
A first optical functional film 4 that functions as a beam splinter with the perpendicularly opposing slopes of a and 3b facing each other.
This is a beam splinter in which the two are integrated and fixed by interposing the two.

Further, the second optical component 5 is connected to the optical lens through a second optical functional film 6 which functions as a polarizing beam splitter between the right-angled opposing slopes of the optical lenses 3a and 3b, which are equivalent to the first optical component 2. This is a polarizing beam splinter in which 3a and 3b are integrated and fixed.

Furthermore, the 172 wavelength plate 7 is configured such that the crystal orientation C axis of a birefringent crystal such as quartz is set at β degrees, for example, 22.5 degrees with respect to the vertical axis Y shown in the figure.
The first optical component 2 is cut and formed in a tilted state.
and the second optical component 5 on the optical axis.

8 is an objective lens, and 9 is a recording medium for optical signals.

Note that 10.11 indicates a photodetector disposed on the optical axis of the laser beam emitted from the second optical component 5.

In such a configuration, for example, the laser beam emitted from the laser light source 1 (
As shown in (■) in B), the laser beam/(P wave) having a polarization plane in the direction parallel to the plane of the paper enters the first optical component 2, then is reflected by the first optical functional film 4 and is transmitted to a monitor (not shown). The laser beam 11 is separated into a part of the laser beam 11 that is emitted in the direction , and a large part of the laser beam 12 that is transmitted through the optical functional film 4 and is emitted as is from the first optical component 2 . In this case, the polarization plane of the laser beam 12 is parallel to the plane of the paper, as shown in (2).

Here, the laser beam 12 is converged by the objective lens 8 and then irradiates a predetermined position on the recording medium 9. At this time, the laser beam 13 reflected from the irradiated portion of the recording medium 9 by the laser beam 12 is
Normally, along with the reflected light of the P wave, the S wave as a signal wave, which is influenced by the condition of the recording medium, is superimposed and mixed into reflected light as shown in (■) with a polarization plane perpendicular to the plane of the paper. It has become.

Then, of the laser beam/3 incident on the first optical component 2, a part of the P wave and all of the S wave constituting the laser beam 13 are reflected by the first optical function film 4, and the optical function is A P wave parallel to the plane containing the normal line and the optical axis and an S wave orthogonal to each other are superimposed, and the laser beam 14 shown in (2) is emitted from the first optical component 2.

Furthermore, the polarization plane of the 172 wave plate 7 is rotated by 2β, that is, 45 degrees in the case of the figure, and it is transmitted as 15 having a polarization plane in the direction shown in ■ in Figure (A), and is transmitted to the second optical component. 5
is configured to be incident on the

In this case, each polarization plane of the P wave and S wave of the laser beam 15 is parallel to the optical functional film 4 of the first optical component 2.
The direction is rotated by 45 degrees with respect to the plane including the normal line of the optical functional film 6 and the optical axis.

Normally, in such a case, the laser beam 15 with a rotated plane of polarization
Of these, the P-wave component is accurately divided into two by the second optical functional film 6 into a transmitting bone and a reflecting bone, and the S-wave component as a signal wave from the recording medium 9 is divided into two parts by the second optical function film 6, and the S-wave component as a signal wave from the recording medium 9 is divided into two parts by the second optical function film 6. It is known that the ratio of transmission to reflection in the second optical functional film 6 varies depending on the state.

Therefore, the laser beams 16 and 17, in which the P wave component and the S wave component that are split by transmission or reflection at the second optical functional film 6 and are emitted from the second optical component are superimposed, are provided on the optical path. The recording medium 9 is detected by the photodetectors 10 and 11 and the difference between the measured values is
information data can be reliably obtained.

However, optical devices with such a configuration require multiple optical circuit elements, which makes it difficult to reduce the price, and requires a lot of man-hours for alignment, such as aligning the optical axes of multiple components and accurately arranging them. This is hindering productivity improvement.

[Problem to be solved by the invention]

In optical circuit components with conventional configurations, multiple components such as beam splinters and wavelength plates are arranged spatially, so there is a problem that it is not possible to miniaturize and lower the cost of optical circuit components. There was a problem in that a large number of man-hours were required for alignment such as alignment and adjustment.

[Means to solve the problem]

The above problem is caused by the first beam splitter functioning as a beam splitter.
The relationship between the film surface of the optical functional film of the optical element and the film surface of the optical functional film of the second optical element functioning as a polarized beam splitter is expressed as follows: This problem is solved by a composite optical component in which the optical elements on one side are arranged so that the optical axes that cross the optical functional films of the elements are aligned at the same predetermined angle, and the optical elements on one side are rotated by a predetermined angle about the optical axis.

[For production]

By integrating a plurality of components constituting an optical circuit component, the optical circuit component can be made smaller and lower in price.

In the present invention, the optical functional film surface of the second optical element forming the polarizing beam splitter is replaced with the optical functional film surface of the second optical element forming the polarizing beam splitter.
The first optical element and the second optical element are integrated in a state in which they are rotated by a predetermined angle about the front axis with respect to the optical functional film surface of the optical element.

Therefore, the laser light that is reflected by the optical functional surface of the first optical element and enters the optical functional film surface of the second optical element will be incident with its plane of polarization rotated by a predetermined angle. This eliminates the need for a wavelength plate, which was conventionally required, making it possible to further reduce the size and cost.

〔Example〕

FIG. 1 is a diagram showing a configuration example of a composite optical component according to the present invention, and FIG. 2 is a configuration diagram showing another embodiment.

In FIG. 1, (A) is a diagram explaining the configuration, and (B) is a diagram showing an application example.

In Figure (A), for ease of understanding, the individual parts are shown in (A) and the integrated composite state is shown in (B).

In (A) of Figure (A), 20 and 21 are optical prisms with the same size and a right-angled isosceles triangle cross section, and the beam splitter is connected with the slopes facing each other with the right angle as the apex angle facing each other. The first optical element 23 is constructed by adhesively fixing the prisms 20 and 21 through an optical functional film 22 having a function.

The second optical element 24 uses the same optical prism 20.21 constituting the first optical element 23, and has an optical functional film having the function of a polarizing beam splitter between the slopes facing the apex angle. The prisms 20 and 21 are adhesively fixed with the prisms 25 interposed therebetween.

Here, one surface (three surfaces in the drawing) sandwiching the apex angle of the prism 21 of the first optical element 23 and one surface (the surface shown) sandwiching the apex angle of the prism 20 of the second optical element 24 are connected to each optical functional film 22. After aligning the central axes, that is, the optical axes, and 25 so that they are parallel and facing each other, only the second optical element 24 is rotated by θ degrees, that is, 45 degrees in the R direction about the optical axis, and then the two are glued together. It is fixed to form a composite optical component 26 shown in FIG.

The composite optical component 26 shown in Figure CB> showing an application example is shown in Figure (
Composite optical components in (b) of ^)? The figure is viewed from the direction indicated by the mark, and the light source 2, objective lens 8, and recording medium 9 are the same as those in FIG. 3.

In such a configuration, the laser light L (P wave) similar to that shown in FIG. A part of the laser beam L1 is emitted in the direction of a monitor (not shown) and is transmitted through the optical functional film 22 to the optical element 23 as it is.
The laser beam L2 is separated into most of the laser beam L2 emitted from the recording medium 9, and the laser beam L2 passes through the objective lens 8 and irradiates a predetermined position on the recording medium 9.

In addition, the irradiation light P wave and the signal wave S reflected from the recording medium 9
In the laser beam L3 on which the waves are superimposed, part of the P wave and all of the S wave are reflected by the first optical functional film 22 and become the laser beam L4, as in the case of FIG. incident on the element 24.

In this case, since the second optical element 24 is rotated by θ degrees, that is, 45 degrees, about the optical axis with respect to the first optical element 23 as described above, the optical functional film 22 of the first optical element 23 The plane including the normal and the optical axis and the plane including the normal and the optical axis of the optical functional film 25 of the second optical element 24 are rotated by 45 degrees about the optical axis.

This means that the relative directional relationship between the polarization plane of the laser beam 15 and the plane containing the optical axis and the normal to the optical functional film 6 of the second optical component 5 in FIG. 3 is exactly the same. It represents.

Therefore, the light is transmitted through the optical functional film 25 of the second optical element 24.

Laser beams L5 and L6, in which the P wave component and the S wave component are superimposed, reflected and emitted from the optical element 24 are detected by photodetectors 27 and 28 provided on their optical paths, respectively, and the difference between the measured values is detected. By detecting this, information data as the recording medium 9 can be obtained in the same way as in the case of FIG.

Therefore, there is no need to provide the wave plate shown in FIG.

Further, FIG. 2 showing another embodiment incorporates a third optical element in order to check the reflected laser beam from the recording medium 9 in the middle of the process, and the other configuration is the same as in FIG. 1. It is similar to

In the figure, both the first optical element 23 and the second optical element 24 are arranged in the same way as those shown in FIG. The optical element 23' is rotated and inserted in the same direction as the second optical element 24, and the whole is fixed by adhesive and integrated.

In this case, since the optical functional film 22'' of the third optical element 23' functions as a beam subrifter, it is not separated depending on the polarization direction, and therefore the laser beam emitted from the third optical element 23' The light L7 can be used to detect the position of a track on the recording medium 9 or to monitor the focusing situation on the surface of the recording medium.

27.28 is the photo detector, respectively.

〔Effect of the invention〕

As described above, since the present invention eliminates the need for a wavelength plate, it is possible to provide a composite optical component that can be made smaller and lower in price by reducing assembly and adjustment man-hours.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a configuration example of a composite optical component according to the present invention, FIG. 2 is a configuration diagram showing another embodiment, and FIG. 3 is a principle diagram showing a configuration example of a conventional optical device. In the figure, 1 is a laser light source, 8 is an objective lens, 9 is a recording medium, 20.21 is a prism, 22.25 is an optical functional film, 2
3, 23', 24 are optical elements, 26 is a composite optical component, (
A) Honjoshi 1 Niborone Village, 1F Exit Figure 1 (Part 1) Figure (Zone 2)

Claims (2)

[Claims] (1) The film surface of the optical functional film (22) of the first optical element (23) functioning as a beam splitter and the optical functional film (25) of the second optical element (24) functioning as a polarizing beam splitter The relationship between the film surface and the optical axis that crosses the optical functional film (22) of the first optical element (23) and the optical functional film (25) of the second optical element (24) at the same predetermined angle, respectively. 1. A composite optical component characterized in that the optical elements on one side are arranged so as to be rotated by a predetermined angle around the optical axis in a matched state. (2) The predetermined angle of the optical axis that crosses the optical functional film of the first optical element and the optical functional film of the second optical element with respect to each optical functional surface is 45 degrees, and 2. The composite optical component according to claim 1, wherein the predetermined rotation angle about the optical axis is 45 degrees.