JP2001147308A - Luminous flux dividing element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a luminous flux dividing element which emits an even number of diffracted rays of light and has enhanced diffraction efficiency. SOLUTION: Many belt-like standard phase patterns P1, P2, etc., which extend in a direction x are formed in parallel on a substrate B at regular pitches in a direction y to obtain the objective luminous flux dividing element 1. The substrate B, including the phase patterns P1, P2, etc., comprises a transparent resin material or a glass material. Each of the phase patterns P1, P2, etc., is formed, in such a way that the phase contrast given in its pitch in the direction y varies nonlinearly. This phase distribution is a composite phase distribution comprising the sum of a 1st phase distribution, in which a phase contact varies in a rectangular wave form with steps of the half-wavelength of incident light and a period T and a duty ratio of 1 are ensured, and a 2nd phase distribution, in which a phase contrast varies nonlinearly and a period is T/2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a grating type light beam splitting element.

[0002]

2. Description of the Related Art A conventional grating type light beam splitting element is disclosed in, for example, Japanese Patent Application Laid-Open Nos.
No. 225305. These publications disclose a light beam splitting element that obtains an odd or even number of diffracted lights by using a rectangular pattern having a single phase height and an uneven width.

[0003]

However, the conventional light beam splitting element described in the above publication has a diffraction efficiency of 70% to 85% in the former embodiment and 81% in the latter embodiment.
Therefore, there is a problem that the intensity of the incident light cannot be used sufficiently effectively, and the loss of light energy is large.

As described in the above-mentioned Japanese Patent Application Laid-Open No. 7-225305, in the field of an optical recording device connected to a computer or an optical computer, the unit of digital operation is 1 byte, that is, 8 bits. Since the calculation is generally performed in even-bit units, even an optical recording device or an optical computer used in these fields may use even-numbered light. Therefore, if the light beam splitting element can also split the light into an even number, the intensity of the incident light can be effectively used without wasting.

The present invention has been made in view of the above-mentioned problems of the prior art, and is a light beam splitting element for generating an even number of diffracted light beams, the light beam splitting efficiency of which is higher than that of the conventional element. It is an object to provide a split element.

[0006]

In order to achieve the above object, a grating-type light beam splitting element according to the present invention provides an overall phase distribution by summing the first and second phase distributions having the following characteristics. Is constituted. In the first phase distribution, the phase difference changes in a rectangular wave shape with a step of a half wavelength of the incident light, the cycle is T, the duty ratio is 1, and
In the second phase distribution, the phase difference changes nonlinearly and the period is T
/ 2, and the incident light is totally separated into an even number of diffracted lights. The first phase distribution splits the incident light into mainly ± first-order diffracted lights, and the second phase distribution splits the incident light mainly into an odd number of diffracted lights.

According to the above configuration, the first phase distribution is:
It has a function of mainly dividing incident light into ± 1st-order diffracted light, and the second phase distribution has a diffraction angle of 2 degrees due to the first phase distribution.
The incident light is split into an odd number of diffracted lights at twice the diffraction angle. For this reason, the diffracted light of a certain order split by the second phase distribution is split into two by the first phase distribution, and similarly,
The diffracted light of the next adjacent order is overlapped. Here, an even number of diffracted lights can be obtained by adjusting the second phase distribution so as to eliminate components that do not overlap with other diffracted lights on the outermost side.

The following three types of first and second phase distributions are conceivable. (1) A phase pattern in which the first and second phase distributions are combined is formed on one surface of a single member. (2) Each phase pattern of the first and second phase distributions is independently formed on different surfaces of a single member. (3) Each phase pattern of the first and second phase distributions is independently formed on different members, and these members are arranged in series along the traveling direction of light. In each case, the optical function is almost the same. From the ease of alignment during actual installation
(1) and (2) are desirable, and (3) is advantageous from the viewpoint of ease of processing.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, three embodiments of a light beam splitting element according to the present invention will be described. In each embodiment, the pattern shown in Example 1 described later is used as the second phase distribution, and an element that divides the incident light into four light beams is configured in combination with the first phase distribution.

FIG. 1 is a perspective view showing a light beam splitting element 1 of the embodiment, and FIG. 2 is a graph showing a phase distribution of the light beam splitting element in FIG. As shown in FIG. 1 in an enlarged manner, the light beam splitting element 1 has band-shaped reference phase patterns P1, P2 extending in the x direction.
Are formed in parallel in the y direction at equal pitches on the substrate B. Substrate B includes reference phase patterns P1, P2,. . . Including transparent resin materials,
Or it is formed of a glass material.

Each of the reference phase patterns P1, P
2,... Are formed such that the phase difference applied within the pitch in the y direction changes nonlinearly. As shown in FIG. 2, the phase distribution changes in a rectangular wave shape with a step of a half wavelength of the incident light, the first phase distribution in which the period is T and the duty ratio is 1, and the phase difference Changes nonlinearly,
This is a composite phase distribution composed of a phase sum with a second phase distribution having a period of T / 2. That is, the light beam splitting element 1 according to the first embodiment has a phase pattern in which the first and second phase distributions are combined formed on one surface of a single member. The incident light is incident parallel to the z direction perpendicular to both the x and y directions.

As shown in FIG. 3A, the first phase distribution has a function of dividing incident light into ± first-order diffracted lights at a diffraction angle θ, and the second phase distribution has a function as shown in FIG. As shown in B), the incident light is converted into an odd number of diffracted lights (0th order, ± 1st order, ± 2nd order 5th order) at a diffraction angle 2θ twice the diffraction angle due to the first phase distribution.
Book).

By combining such first and second phase distributions, each order of diffracted light divided by the second phase distribution is divided into two by the first phase distribution. Here, since the diffraction angle θ according to the first phase distribution is の of the diffraction angle 2θ according to the second phase distribution, the diffracted light of each order divided into two is similarly divided into two adjacent orders. Overlap with the diffracted light. That is, as shown by the broken line in FIG. 3C, the 0th-order light is divided into L1 and L2, and the -1st-order light is divided into L1 and L2.
The third and +1 order lights are divided into L2 and L4, the -second order light is divided into L3 and L5, and the +2 order light is divided into L4 and L6. Here, by elimination of the components L5 and L6 which are the outermost and do not overlap with the other diffracted lights, four diffracted lights L1, L2, L3 and L4 can be obtained as shown in FIG. 3 (D). .

According to the above configuration, an even number of diffracted lights can be efficiently generated. In general, when a diffraction grating is used, plus or minus diffracted light appears symmetrically with respect to the 0th-order diffracted light (transmitted light), and an odd number of diffracted lights can be obtained as a whole. The light beam splitting element 1 of the embodiment generates an even number of diffracted lights by combining the first phase distribution and the second phase distribution having different periods from each other.

Note that the description of FIG. 3 is for most light and is not accurate in a strict sense. That is, in the first phase distribution, 100% of the incident light cannot be theoretically separated into ± first-order lights, but only 81% thereof can be separated into ± first-order diffracted lights. Therefore, the remaining 19% of the light is ±
It becomes third-order and ± 5-order diffracted light. For this reason, even if the second phase distribution is superimposed, even-numbered branches cannot be obtained in a strict sense. Also, the outermost diffracted light component L
It is necessary to erase 5, L6. Therefore, in the actual design, the first and second phase distributions (initial values) are input to a computer and superimposed, and L5, L
The second phase distribution is finely adjusted for the purpose of erasing step 6 and equal branching of the remaining even number of diffracted lights. In this sense, the adjusted second phase distribution does not always allow the incident light to be equally divided into odd numbers.

A diffraction grating having a complicated phase pattern in which the phase difference changes nonlinearly as in the first embodiment is as follows:
It cannot be accurately engraved with normal lithography techniques. Therefore, here, a mold serving as a master is created by a mechanical engraving method using a lathe, and a light beam splitting element is created by transferring the engraved master pattern to resin or optical glass.

FIG. 4A is a side view of the light beam splitting element 2 according to the second embodiment. The light beam splitting element 2 is formed by forming a phase pattern of a first phase distribution on one surface of a single member and forming a phase pattern of a second phase distribution on the other surface.

FIG. 4B is a side view of the light beam splitting element 3 according to the third embodiment. The light beam splitting element 3 includes a first member 3 on which a phase pattern of a first phase distribution is formed.
a and a second phase pattern in which a phase pattern of a second phase distribution is formed.
And the member 3b are arranged in series along the traveling direction of light with the phase patterns facing each other.

Since the phase pattern of the first phase distribution in the second and third embodiments only controls the depth corresponding to a half wavelength, it can be easily formed by ordinary lithography. On the other hand, the phase pattern of the second phase distribution can be formed by the machine marking method as in the first embodiment.

Next, 14 examples of the configuration of the light beam splitting element as a specific example based on the first embodiment will be described. Example 1 is an element that splits an incident light beam into four diffracted lights, Examples 2 and 3 are elements that splits incident light into six diffracted lights, and Examples 4 to 6 are those that split an incident light beam into eight diffracted lights. Examples 7 and 8 are elements that split an incident light beam into ten diffracted lights, Examples 9 and 10 are elements that split an incident light beam into twelve diffracted lights, and Examples 11 and 12 are incident light. Embodiments 13 and 14 are examples of elements that split an incident light beam into 16 diffracted lights.

[0021]

Embodiment 1 Table 1 shows a second phase distribution used in the light beam splitting element of Embodiment 1. This table shows that the light at each coordinate obtained by equally dividing one pitch (period T / 2) of the second phase distribution into 32 coordinates of 1 to 32 along the y direction of FIG. 1, that is, the parallel direction of the phase pattern. And its unit is radian.

[0022]

[Table 1]

Table 2 shows a composite phase distribution in which the second phase distribution shown in Table 1 is overlapped with the first phase distribution on the same plane as described in the first embodiment. This table is
One pitch (period T) of the composite phase distribution is shown in FIG. 1 in the y direction, that is, the light phase at each coordinate which is equally divided into 64 coordinates of 1 to 64 along the parallel direction of the phase pattern. The unit is radian.

[0024]

[Table 2]

When the actual shape of the phase pattern is expressed as a distance in the traveling direction of light (z direction in FIG. 1) from a point having a phase difference of 0, the wavelength used is λ, assuming use in air. ,
The phase x λn / (2π (n-1)), where n is the refractive index of the element
Required by FIG. 5 is a graph showing the composite phase distribution of the light beam splitting element of Example 1 shown in Table 2, in which the vertical axis represents the phase and the horizontal axis represents the coordinates.

Table 3 shows the light beam splitting performance of the light beam splitting element having the reference phase pattern shown in Table 2. Assuming that the intensity of the incident light is 1, the light amount of each divided light beam is -15th order to +
The figure shows the fifteenth odd-order diffracted light. Since all the even-order light amounts are 0, they are omitted. The “diffraction efficiency” indicates a ratio of the intensity of the diffracted light of the number of divisions targeted by each embodiment to the intensity of the incident light beam.
In the figure, the ratio of the sum of the four diffracted light intensities of -3, -1, 1 and 3 to the intensity 1 of the incident light flux is shown. FIG.
Is a graph showing the intensity distribution of the diffracted light shown in Table 3. In this graph, the horizontal axis indicates the order of the diffracted light, and the vertical axis indicates the intensity of the diffracted light of each order when the intensity of the incident light is 1.

[0027]

[Table 3]

[0028]

Embodiment 2 Table 4 shows a second phase distribution used in the light beam splitting element of Example 2, and Table 5 shows the second phase distribution shown in Table 4 in the first embodiment. As described above, a composite phase distribution superimposed on the first phase distribution on the same plane is shown. FIG. 7 is a graph showing a composite phase distribution of the light beam splitting element of Example 2 shown in Table 5.

[0029]

[Table 4]

[0030]

[Table 5]

Table 6 shows the light beam splitting performance of the light beam splitting element having the reference phase pattern shown in Table 5. FIG. 8 is a graph showing the intensity distribution of the diffracted light shown in Table 6.

[0032]

[Table 6]

[0033]

[Embodiment 3] Table 7 shows a second phase distribution used in the light beam splitting element of Embodiment 3, and Table 8 shows the second phase distribution shown in Table 7 in the first embodiment. As described above, a composite phase distribution superimposed on the first phase distribution on the same plane is shown. FIG. 9 is a graph showing a composite phase distribution of the light beam splitting element of Example 3 shown in Table 8.

[0034]

[Table 7]

[0035]

[Table 8]

Table 9 shows the beam splitting performance of the beam splitter having the reference phase pattern shown in Table 8. FIG.
10 is a graph showing the intensity distribution of the diffracted light shown in Table 9.

[0037]

[Table 9]

[0038]

Embodiment 4 Table 10 shows the second phase distribution used in the light beam splitting element of Example 4, and Table 11 shows the second phase distribution shown in Table 10 in the first embodiment. As described above, a composite phase distribution superimposed on the first phase distribution on the same plane is shown. FIG. 11 is a graph showing a composite phase distribution of the light beam splitting element of Example 4 shown in Table 11.

[0039]

[Table 10]

[0040]

[Table 11]

Table 12 shows the beam splitting performance of the beam splitter having the reference phase pattern shown in Table 11. FIG.
Is a graph showing the intensity distribution of the diffracted light shown in Table 12.

[0042]

[Table 12]

[0043]

Fifth Embodiment Table 13 shows the second phase distribution used in the light beam splitting element of the fifth embodiment, and Table 14 shows the second phase distribution shown in Table 13 in the first embodiment. As described above, a composite phase distribution superimposed on the first phase distribution on the same plane is shown. FIG. 13 is a graph showing a composite phase distribution of the light beam splitting element of Example 5 shown in Table 14.

[0044]

[Table 13]

[0045]

[Table 14]

Table 15 shows the beam splitting performance of the beam splitter having the reference phase pattern shown in Table 14. FIG.
Is a graph showing the intensity distribution of the diffracted light shown in Table 15.

[0047]

[Table 15]

[0048]

[Embodiment 6] Table 16 shows the second phase distribution used in the light beam splitting element of Embodiment 6, and Table 17 shows the second phase distribution shown in Table 16 in the first embodiment. As described above, a composite phase distribution superimposed on the first phase distribution on the same plane is shown. FIG. 15 is a graph showing a composite phase distribution of the light beam splitting element of Example 6 shown in Table 17.

[0049]

[Table 16]

[0050]

[Table 17]

Table 18 shows the light beam splitting performance of the light beam splitting element having the reference phase pattern shown in Table 17. FIG.
Is a graph showing the intensity distribution of the diffracted light shown in Table 18.

[0052]

[Table 18]

[0053]

[Embodiment 7] Table 19 shows the second phase distribution used in the light beam splitting element of Example 2, and Table 20 shows the second phase distribution shown in Table 19 in the first embodiment. As described above, a composite phase distribution superimposed on the first phase distribution on the same plane is shown. FIG. 17 is a graph showing a composite phase distribution of the light beam splitting element of Example 7 shown in Table 20.

[0054]

[Table 19]

[0055]

[Table 20]

Table 21 shows the light beam splitting performance of the light beam splitting element having the reference phase pattern shown in Table 20. FIG.
Is a graph showing the intensity distribution of the diffracted light shown in Table 21.

[0057]

[Table 21]

[0058]

[Embodiment 8] Table 22 shows the second phase distribution used in the light beam splitting element of Example 8, and Table 23 shows the second phase distribution shown in Table 22 in the first embodiment. As described above, a composite phase distribution superimposed on the first phase distribution on the same plane is shown. FIG. 19 is a graph showing a composite phase distribution of the light beam splitting element of Example 8 shown in Table 23.

[0059]

[Table 22]

[0060]

[Table 23]

Table 24 shows the beam splitting performance of the beam splitter having the reference phase pattern shown in Table 23. FIG.
Is a graph showing the intensity distribution of the diffracted light shown in Table 24.

[0062]

[Table 24]

[0063]

Ninth Embodiment Table 25 shows a second phase distribution used in the light beam splitting element of the ninth embodiment, and Table 26 shows the second phase distribution shown in the table 25 in the first embodiment. As described above, a composite phase distribution superimposed on the first phase distribution on the same plane is shown. FIG. 21 is a graph showing a composite phase distribution of the light beam splitting element of Example 9 shown in Table 26.

[0064]

[Table 25]

[0065]

[Table 26]

Table 27 shows the beam splitting performance of the beam splitting element having the reference phase pattern shown in Table 26. FIG.
Is a graph showing the intensity distribution of the diffracted light shown in Table 27.

[0067]

[Table 27]

[0068]

[Embodiment 10] Table 28 shows the second phase distribution used in the light beam splitting element of Example 10, and Table 29 shows the second phase distribution shown in Table 28 in the first embodiment. As described above, a composite phase distribution superimposed on the first phase distribution on the same plane is shown. FIG. 23 is a graph showing a composite phase distribution of the light beam splitting element of Example 10 shown in Table 29.

[0069]

[Table 28]

[0070]

[Table 29]

Table 30 shows the beam splitting performance of the beam splitting element having the reference phase pattern shown in Table 29. FIG.
Is a graph showing the intensity distribution of the diffracted light shown in Table 30.

[0072]

[Table 30]

[0073]

Embodiment 11 Table 31 shows the second phase distribution used in the light beam splitting element of Example 11, and Table 32 shows the second phase distribution shown in Table 31 in the first embodiment. As described above, a composite phase distribution superimposed on the first phase distribution on the same plane is shown. FIG. 25 is a graph showing a composite phase distribution of the light beam splitting element of Example 2 shown in Table 32.

[0074]

[Table 31]

[0075]

[Table 32]

Table 33 shows the beam splitting performance of the beam splitter having the reference phase pattern shown in Table 32. FIG.
Is a graph showing the intensity distribution of the diffracted light shown in Table 33.

[0077]

[Table 33]

[0078]

Embodiment 12 Table 34 shows the second phase distribution used in the light beam splitting element of Example 12, and Table 35 shows the second phase distribution shown in Table 34 in the first embodiment. As described above, a composite phase distribution superimposed on the first phase distribution on the same plane is shown. FIG. 27 is a graph showing a composite phase distribution of the light beam splitting element of Example 12 shown in Table 35.

[0079]

[Table 34]

[0080]

[Table 35]

Table 36 shows the beam splitting performance of the beam splitting element having the reference phase pattern shown in Table 35. FIG.
Is a graph showing the intensity distribution of the diffracted light shown in Table 36.

[0082]

[Table 36]

[0083]

Embodiment 13 Table 37 shows the second phase distribution used in the light beam splitting element of Embodiment 13, and Table 38 shows the second phase distribution shown in Table 37 in the first embodiment. As described above, a composite phase distribution superimposed on the first phase distribution on the same plane is shown. FIG. 29 is a graph showing a composite phase distribution of the light beam splitting element of Example 13 shown in Table 38.

[0084]

[Table 37]

[0085]

[Table 38]

Table 39 shows the light beam splitting performance of the light beam splitting element having the reference phase pattern shown in Table 38. FIG.
Is a graph showing the intensity distribution of the diffracted light shown in Table 39.

[0087]

[Table 39]

[0088]

Embodiment 14 Table 40 shows the second phase distribution used in the light beam splitting element of Embodiment 14, and Table 41 shows the second phase distribution shown in Table 40 in the first embodiment. As described above, a composite phase distribution superimposed on the first phase distribution on the same plane is shown. FIG. 31 is a graph showing a composite phase distribution of the light beam splitting element of Example 14 shown in Table 41.

[0089]

[Table 40]

[0090]

[Table 41]

Table 42 shows the beam splitting performance of the beam splitting element having the reference phase pattern shown in Table 41. FIG.
Is a graph showing the intensity distribution of the diffracted light shown in Table 42.

[0092]

[Table 42]

According to each embodiment, the diffraction efficiency can be increased to a minimum of about 89% and a maximum of about 98%.

[0094]

As described above, according to the present invention, the incident light having the first phase distribution that divides the incident light into ± 1st-order diffracted light and half the period of the first phase distribution is formed. By forming the entire phase distribution by the phase sum with the second phase distribution that is split into odd-numbered diffracted lights, incident light can be split into even-numbered diffracted lights with higher diffraction efficiency than before.

[Brief description of the drawings]

FIG. 1 is an enlarged perspective view showing a phase pattern of a light beam splitting element according to a first embodiment.

FIG. 2 is a graph showing a phase distribution of the light beam splitting element according to the first embodiment.

FIG. 3 is an explanatory diagram showing an operation of first and second phase distributions and an operation of a composite phase distribution in the first embodiment.

FIG. 4 is a side view of a light beam splitting element according to the second and second embodiments.

FIG. 5 is a graph showing a composite phase distribution of a four-division light beam splitting element according to the first embodiment.

FIG. 6 is a graph showing an intensity distribution of diffracted light by the light beam splitting element according to the first embodiment.

FIG. 7 is a graph showing a composite phase distribution of a six-segment light beam splitting element according to the second embodiment.

FIG. 8 is a graph showing the intensity distribution of diffracted light by the light beam splitting element according to the second embodiment.

FIG. 9 is a graph showing a composite phase distribution of a six-segment light beam splitting element according to the third embodiment.

FIG. 10 is a graph showing an intensity distribution of diffracted light by the light beam splitting element according to the third embodiment.

FIG. 11 is a graph showing a composite phase distribution of an eight-segment light beam splitting element according to a fourth embodiment.

FIG. 12 is a graph showing an intensity distribution of diffracted light by the light beam splitting element according to the fourth embodiment.

FIG. 13 is a graph showing a composite phase distribution of an eight-segment light beam splitting element according to a fifth embodiment.

FIG. 14 is a graph showing the intensity distribution of diffracted light by the light beam splitting element according to the fifth embodiment.

FIG. 15 is a graph showing a composite phase distribution of an eight-segment light beam splitting element according to the sixth embodiment.

FIG. 16 is a graph showing an intensity distribution of diffracted light by the light beam splitting element according to the sixth embodiment.

FIG. 17 is a graph illustrating a composite phase distribution of a ten-segment light beam splitting element according to the seventh embodiment.

FIG. 18 is a graph showing an intensity distribution of diffracted light by the light beam splitting element according to the seventh embodiment.

FIG. 19 is a graph showing a composite phase distribution of a ten-segment light beam splitting element according to an eighth embodiment.

FIG. 20 is a graph showing the intensity distribution of the diffracted light by the light beam splitting element according to the eighth embodiment.

FIG. 21 is a graph showing a composite phase distribution of a 12-division light beam splitting element according to a ninth embodiment.

FIG. 22 is a graph showing the intensity distribution of the diffracted light by the light beam splitting element according to the ninth embodiment.

FIG. 23 is a graph showing a composite phase distribution of a 12-split type light beam splitting element according to the tenth embodiment.

FIG. 24 is a graph showing the intensity distribution of the diffracted light by the light beam splitting element according to the tenth embodiment.

FIG. 25 is a graph showing a composite phase distribution of a 14-split type light beam splitting element according to the eleventh embodiment.

FIG. 26 is a graph showing the intensity distribution of the diffracted light by the light beam splitting element according to the eleventh embodiment.

FIG. 27 is a graph showing a composite phase distribution of a 14-segment light beam splitting element according to the twelfth embodiment.

FIG. 28 is a graph showing the intensity distribution of the diffracted light by the light beam splitting element of Example 12.

FIG. 29 is a graph showing a composite phase distribution of a 16-segment light beam splitting element according to the thirteenth embodiment.

FIG. 30 is a graph showing the intensity distribution of the diffracted light by the light beam splitting element according to the thirteenth embodiment.

FIG. 31 is a graph showing a composite phase distribution of a 16-split type light beam splitting element of Example 14.

FIG. 32 is a graph showing the intensity distribution of the diffracted light by the light beam splitting element of Example 14.

[Explanation of symbols]

 1 Beam splitting elements P1, P2, ... Reference phase pattern B Substrate

Claims (18)

[Claims] 1. A grating-type light beam splitting element for diffracting incident light to split the light into a plurality of light beams, wherein the phase difference changes into a rectangular wave shape with a half-wave step of the incident light, the period is T, and the duty is The entire phase distribution is composed of the phase sum of the first phase distribution whose ratio is 1 and the second phase distribution whose phase difference changes nonlinearly and whose period is T / 2. 2. The light beam splitting device according to 2, wherein the phase distribution as a whole separates incident light into an even number of diffracted lights. 2. The light beam splitting element according to claim 1, wherein the phase pattern obtained by combining the first and second phase distributions is formed on one surface of a single member. 3. The light beam splitter according to claim 1, wherein each of the phase patterns for generating the first and second phase distributions is independently formed on different surfaces of a single member. element. 4. The apparatus according to claim 1, wherein each of the phase patterns producing the first and second phase distributions is formed on a different member, and these members are arranged in series along the traveling direction of light. 2. The light beam splitting element according to 1. 5. The second phase distribution has a range of 3 within a unit cycle.
The phase at each coordinate position when equally divided into two is formed so as to be within a predetermined error range centered on the following value, and the incident light is divided into four parts in accordance with the first phase distribution. The light beam splitting element according to claim 1, wherein: 6. The second phase distribution is 3 within a unit period.
The phase at each coordinate position when equally divided into two is formed so as to fall within a predetermined error range centered on the following value, and the incident light is divided into six parts in accordance with the first phase distribution. The light beam splitting element according to claim 1, wherein: 7. The second phase distribution has a unit period within 3
The phase at each coordinate position when equally divided into two is formed so as to be within a predetermined error range centered on the following value, and the incident light is divided into six parts in accordance with the first phase distribution. The light beam splitting element according to claim 1, wherein: 8. The second phase distribution includes three within a unit cycle.
The phase at each coordinate position when equally divided into two is formed so as to fall within a predetermined error range centered on the following value, and the incident light is divided into eight in accordance with the first phase distribution. The light beam splitting element according to claim 1, wherein: 9. The method according to claim 1, wherein the second phase distribution is 3 within a unit cycle.
The phase at each coordinate position when equally divided into two is formed so as to fall within a predetermined error range centered on the following value, and the incident light is divided into eight in accordance with the first phase distribution. The light beam splitting element according to claim 1, wherein: 10. The second phase distribution is formed such that a phase at each coordinate position when a unit cycle is equally divided into 32 falls within a predetermined error range centered on the following value:
The light beam splitting element according to any one of claims 1 to 4, wherein incident light is split into eight in accordance with the first phase distribution. 11. The second phase distribution is formed such that a phase at each coordinate position when a unit cycle is equally divided into 32 falls within a predetermined error range centered on the following value:
The light beam splitting device according to any one of claims 1 to 4, wherein incident light is split into ten portions in accordance with the first phase distribution. 12. The second phase distribution is formed such that the phase at each coordinate position when a unit cycle is equally divided into 32 falls within a predetermined error range centered on the following value:
The light beam splitting device according to any one of claims 1 to 4, wherein incident light is split into ten portions in accordance with the first phase distribution. 13. The second phase distribution is formed such that the phase at each coordinate position when a unit cycle is equally divided into 32 falls within a predetermined error range centered on the following value:
The light beam splitting element according to any one of claims 1 to 4, wherein incident light is split into 12 light beams in accordance with the first phase distribution. 14. The second phase distribution is formed such that the phase at each coordinate position when the unit period is equally divided into 32 falls within a predetermined error range centered on the following value:
The light beam splitting element according to any one of claims 1 to 4, wherein incident light is split into 12 light beams in accordance with the first phase distribution. 15. The second phase distribution is formed such that a phase at each coordinate position when a unit cycle is equally divided into 32 falls within a predetermined error range centered on the following value:
The light beam splitting element according to any one of claims 1 to 4, wherein incident light is split into 14 portions in accordance with the first phase distribution. 16. The second phase distribution is formed such that the phase at each coordinate position when the unit period is equally divided into 32 falls within a predetermined error range centered on the following value:
The light beam splitting element according to any one of claims 1 to 4, wherein incident light is split into 14 portions in accordance with the first phase distribution. 17. The second phase distribution is formed such that the phase at each coordinate position when a unit cycle is equally divided into 32 falls within a predetermined error range centered on the following value:
The light beam splitting element according to any one of claims 1 to 4, wherein incident light is split into 16 portions in accordance with the first phase distribution. 18. The second phase distribution is formed such that a phase at each coordinate position when a unit cycle is equally divided into 32 falls within a predetermined error range centered on the following value:
The light beam splitting element according to any one of claims 1 to 4, wherein incident light is split into 16 portions in accordance with the first phase distribution.