JPS628103A - Polarizing element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a polarizing element, and more particularly to a polarizing element used as a polarizing prism.

(Prior Art) Polarizing prisms are used in original pickups for digital audio discs, etc., and in various measuring devices that utilize polarized light.

Conventionally, as a polarizing element used as a polarizing prism, one using a thin plate of calcite is known (Applied Physics 35 (15) 55 (1966)). However, since it is difficult to artificially grow calcite crystals, naturally produced calcite must be used, and as a result, polarizing elements using calcite have the problem of high manufacturing costs.

(Objective) The present invention has been made in view of the above-mentioned matters, and aims to provide a novel polarizing element that can be realized at low cost and has the same performance as that using calcite.

(composition) The present invention will be explained below.

The polarizing element of the present invention has a structure in which it is sandwiched between light-transmitting optical members that are thin layers of single crystal KIO3 or BaCO3.

Single crystals of KIO3 and BaCO3 can be easily grown artificially.

This will be explained below with reference to the drawings.

Figure 1 shows an example of the basic configuration of a polarizing element using a single crystal of KIO3. In the figure, numeral 10 is a single crystal thin layer of KIO3, numeral 12. 14 indicates a translucent optical member, respectively.

In the example, the material of the translucent optical members 12 and 14 is
Glass (SFS-1, nd=1.932).

The thin layer 10 is cut out from a single crystal of KIO3, and the difference in principal refractive index determined from its optical elastic axis is maximum for light incident perpendicularly to the left side of the element. It is cut out to look like this. Corners A, B, C, D in the diagram,
E, F, G, and H are A=65° and B=115, respectively.
°, C=D=65°, E=72.10. F=650
．． C)=+550. H=115°. Moreover, the principal refractive index of the thin layer cut out as above is nα=i,
7oo, nβ=1.828, town=1.832.

When light is incident on this element, a portion of the light passes through the thin layer 10.
is transmitted and exits from the element as transmitted light, while the others are 5 thin layers 1
It is totally reflected from 0Vc and exits from the element as totally reflected light. Both the transmitted light and the totally reflected light are linearly polarized light, and their polarization planes are orthogonal to each other.

Note that the bonding surface between the thin layer 10 and the translucent optical member 12, 14 is polished to a sufficiently high accuracy so that no air layer is formed at the bonding portion.

Figure 2 shows an example of the basic configuration of a polarizing element using a single crystal thin layer 10A of BaCO3. In this example as well, the material of the translucent optical members 12A and 14A is glass (SF
S -1,n,1 = 1.923), and the translucent optical members 12A and 14A are right-angled prisms having the same shape.

The thin layer 10A is cut from a single crystal of BaCO3, and the difference in principal refractive index determined from its optical elastic axis is maximum for a ray of light incident perpendicularly to the left side of the element. It is cut out like this. That is, specifically,
Determine the optical axis and the optical elastic axis using a polarizing microscope,
For the above incident light beam, the refractive index of the single crystal is maximum (nr)
, is cut out so that the minimum (nα) is obtained. It goes without saying that the bonding surfaces between the thin layer 10A and the translucent optical members 12A and 14A are polished with high precision in order to avoid the generation of an air layer. In the figure, angle J = 8 =
35°, angle L = T = 55°, angle P = U = 55°
, angle M=69.9°, angle Q=200. Angle R=41.1
It is 0. The main refractive index of the thin layer 10A is nα=1.52
9, nβ=1.676, nr=1.67
It is 7.

This will be explained below based on a specific actual case.

(Actual leakage example 1) In this example, a single crystal of KIO3 was used.

The single crystal of KIO3 belongs to the monoclinic system or the triclinic system,
The fish populations have been determined to be C2, C8 and C1.

Single crystal growth of KIO3 is carried out using HIO3 in an aqueous solution method.
The temperature difference method was used. That is, about 5 grams more KIO3 than the saturation 1 at a predetermined growth temperature,
About 15% of HIO3 was mixed with this KIC15, and the mixture was heated and dissolved in pure water to obtain a mother liquor.

This mother liquor was put into a crystal growth beaker (diameter 30 yn) in a water bath set at a temperature of 45°C, and after the growth liquid was brought to a steady state, a seed crystal suspended from a platinum wire was immersed. At this time, the temperature difference in the mother liquor is 2.5℃
Met. A water bath was placed in a constant temperature bath for crystal growth. After 15 days of growth, crystals approximately 7 dragon horns in size were obtained.

From this crystal, length and width are 5 dragons, thickness is 0.5. 1. 1.5
Three types of deflection elements having the configurations shown in Figure 1 were fabricated by cutting out six types of thin layers with a diameter of 1 mm. The extinction ratios of these 3@ polarizing elements were measured. The results are shown in Table 1VC.

Table 1 (Example 2) In Example 1, 5% of the crystals were cloudy, so the HID3 in the mother liquor was reduced from 15% to 10%, and the crystals were grown under the same conditions as in Example 1. From the obtained crystal, we cut out six types of thin layers, each having a length of 5 mm and a thickness of 0.5 mm, 1.0 mm, and 1.5 mm, and polarized light with the configuration shown in Figure 1. Six types of elements were manufactured. The measurement results of the extinction ratio of these six types of deflection elements are shown in Table 2.
Shown below.

Table 2 As is clear from the actual winding example 1.2, the extinction ratio is affected by the crystalline state of the KIO3 single crystal, and whether it is a good quality single crystal or not. A polarizing element with sufficient performance can be produced by growing the crystal (VC can be sufficiently controlled by controlling the growth of the crystal).

(Leprosy Example 6) From a single crystal of BaCO3 obtained by hydrothermal synthesis, a crystal with a length of 6 mm, a width of 6 nm, a thickness of 0.5 mttt, and 1.01111
1. Three types of thin layers of 1.5 mm were cut out and these 6
Using the thin layer of seeds, six types of polarizing elements having the configurations shown in Figure 2 were prepared, and the extinction ratio of each was measured. Table 6 shows the results.
Shown below.

These three types of polarizing elements in Example 6 in the table are fully usable for practical use, but by controlling the growth conditions of the single crystal and using higher quality crystals, it is possible to further improve the extinction ratio. It is possible to improve.

(effect〕 As described above, according to the present invention, a novel polarizing element can be provided.

KIO3 and BaCO3 used in the polarizing element of the present invention
Since single crystals can be grown artificially, they can be obtained at low cost. Therefore, the polarizing element itself can be realized at low cost. Furthermore, the polarizing element of the present invention not only has a good extinction ratio and is fully usable for practical use, but also has the ability to obtain high-quality crystals by controlling crystal growth conditions. It is also possible to achieve performance comparable to that of

[Brief explanation of the drawing]

, 71 are diagrams showing an example of the basic configuration of a polarizing element using a single crystal of KIO3, and Figure 2 is a diagram showing an example of the basic configuration of a polarizing element using a single crystal of CaCO3. 10...KIO3 single crystal thin layer, IOA...Ca
Single crystal thin layer of CCl3, 12. 12A, 14.
14A... Translucent optical member (1 sparrow)

Claims (1)

[Claims] A polarizing element made by sandwiching a thin layer of KIO_3 or BaCO_3 single crystal between transparent optical members.