KR100843379B1 - Optical modulator using optical path-difference - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to an optical modulator, and in particular, a beam splitter is used to separate incident light and send some separated beams to a driving pixel array, and some to a fixed mirror or another driving pixel array to reflect the optical path difference between the two lights. The present invention relates to an optical modulator using an optical path difference that causes an image plane to form an image by causing constructive or destructive interference in an image plane.

Optical Modulator, Micro Mirror, Micro Mirror Array, Optical Path Difference

Description

Optical modulator using optical path-difference

1 illustrates a prior art electrostatic grating light modulator.

2 is a diagram illustrating reflecting incident light in a state where the electrostatic grating light modulator of the prior art is not deformed.

3 shows a diffraction of incident light in a state in which a prior art grating light modulator is deformed by electrostatic force.

4 is a side view of a diffractive thin film piezoelectric micromirror with depressions having a piezoelectric material in the prior art;

5A is a structural diagram of an optical modulator using an optical path difference according to a first embodiment of the present invention, and FIG. 5B is a structural diagram of an optical modulator using an optical path difference according to a second embodiment of the present invention.

6 is a structural diagram of an optical modulator using an optical path difference according to a third exemplary embodiment of the present invention.

7A through 7C are structural diagrams of the thin film piezoelectric elements of the driving pixel array of FIGS. 5A, 5B, and 6.

8A-8D are structural diagrams of the thick film piezoelectric elements of the driving pixel arrays of FIGS. 5A, 5B, and 6;

In particular, the optical modulator of the present invention uses a beam splitter to separate incident light and send some separated beams to a driving pixel array, and some to a fixed mirror or another driving pixel array to reflect the optical path difference between the two lights. The present invention relates to an optical modulator using an optical path difference that causes an image plane to form an image by causing constructive or destructive interference in an image plane.

In general, optical signal processing has advantages of high speed, parallel processing capability, and large-capacity information processing, unlike conventional digital information processing, which cannot process a large amount of data and real-time processing, and design a binary phase filter using spatial light modulation theory. Research on fabrication, optical logic gates, optical amplifiers, image processing techniques, optical devices, optical modulators, etc.

The dual spatial optical modulator is used in the fields of optical memory, optical display, printer, optical interconnection, hologram, and the like, and research on the development of a display device using the same is underway.

Such a spatial light modulator is, for example, a reflective deformable grating light modulator 10 as shown in FIG. 1. Such a modulator 10 is disclosed in US Pat. No. 5,311,360 to Bloom et al. The modulator 10 includes a plurality of regularly spaced deformable reflective ribbons 18 having reflective surface portions and suspended above the substrate 16. An insulating layer 11 is deposited on the silicon substrate 16. Next, deposition of the sacrificial silicon dioxide film 12 and the low stress silicon nitride film 14 is followed.

The nitride film 14 is patterned from the ribbon 18 and a portion of the silicon dioxide layer 12 is etched so that the ribbon 18 is retained on the oxide spacer layer 12 by the nitride frame 20.

In order to modulate light with a single wavelength [lambda] _O , the modulator is designed such that the thickness of the ribbon 18 and the thickness of the oxide spacer 12 are [lambda] _O / 4.

The lattice amplitude of this modulator 10, defined by the vertical distance d between the reflective surface 22 on the ribbon 18 and the reflective surface of the substrate 16, is the ribbon 18 (the ribbon 16 serving as the first electrode). Is controlled by applying a voltage between the reflective surface 22 of the substrate 16 and the substrate 16 (the conductive film 24 under the substrate 16 serving as the second electrode).

In the undeformed state, i.e. without any voltage applied, the grating amplitude is equal to λ _O / 2 and the total path difference between the ribbon and the light reflected from the substrate is equal to λ _O , thus reinforcing the phase to this reflected light. Let's do it.

Thus, in the undeformed state, the modulator 10 reflects light as a planar mirror. The undeformed state is indicated as 20 in FIG. 2 showing incident light and reflected light.

When a proper voltage is applied between the ribbon 18 and the substrate 16, electrostatic forces deform the ribbon 18 in the down position toward the surface of the substrate 16. In the down position, the grating amplitude is changed like a λ _O / 4. The total path difference is 1/2 of the wavelength, and the light reflected from the modified ribbon 18 and the light reflected from the substrate 16 have a destructive interference.

As a result of this interference, the modulator diffracts incident light 26. The modified state is represented by 28 and 30 in FIG. 3, showing light diffracted in the +/- diffraction modes (D + 1, D-1).

However, BLUM's optical modulator uses an electrostatic method to control the position of the micromirror, in which case the operating voltage is relatively high (usually around 30V) and the relationship between applied voltage and displacement is not linear. There is a disadvantage that the reliability is not high in controlling the light.

In order to solve this problem, Korean Patent Application No. P2003-077389 discloses a "thin film piezoelectric optical modulator and its manufacturing method."

4 is a cross-sectional view of a recessed thin film piezoelectric optical modulator according to the related art.

Referring to the drawings, the recessed thin film piezoelectric optical modulator according to the related art includes a silicon substrate 401 and an element 410.

Here, the element 410 has a constant width and a plurality of constant alignment to form a recessed thin film piezoelectric optical modulator. In addition, the elements 410 have different widths and are alternately arranged to form a recessed thin film piezoelectric optical modulator. In addition, the elements 410 may be spaced apart from each other at a predetermined interval (almost the same distance as the width of the element 410), in which case the micromirror layer formed on all of the upper surface of the silicon substrate 401 is incident Reflects and diffracts light.

The silicon substrate 401 has a recessed portion to provide an air space to the element 410, an insulating layer 402 is deposited on the upper surface, and end portions of the element 410 are attached to both sides of the recessed portion. .

The element 410 has a rod shape, and the bottom surfaces of both ends are attached to both side regions outside the recessed portion of the silicon substrate 401 so that the center portion is spaced apart from the recessed portion of the silicon substrate 401. The portion located in the depression of the 401 includes a lower support 411 movable up and down.

In addition, the element 410 is stacked on the left end of the lower support 411, and is laminated on the lower electrode layer 412 and the lower electrode layer 412 to provide a piezoelectric voltage, and contraction and A piezoelectric material layer 413 that expands to generate a vertical driving force, and an upper electrode layer 414 that is stacked on the piezoelectric material layer 413 and provides a piezoelectric voltage to the piezoelectric material layer 413.

In addition, the element 410 is stacked on the right end of the lower support 411, and is laminated on the lower electrode layer 412 'and the lower electrode layer 412' for providing a piezoelectric voltage. A piezoelectric material layer 413 'that contracts and expands to generate a vertical driving force, and an upper electrode layer 414' that is stacked on the piezoelectric material layer 413 'and provides a piezoelectric voltage to the piezoelectric material layer 413'. Doing.

In addition, Korean Patent Application No. P2003-077389 describes the derived type in addition to the depression type described above.

On the other hand, the optical modulator of the type described in the patent of Bloom, Samsung Electro-Mechanics, etc. can be used as an element for displaying an image. In this case, at least two adjacent elements may form one pixel. Of course, three may be one pixel, four may be one pixel, or six may be one pixel.

However, optical modulators of the kind described in the patents of Bloom, Samsung Electro-Mechanics, etc. have certain limitations in achieving miniaturization. That is, no matter how small the width of the element of the optical modulator can be less than 3㎛, there is a limit that the distance between the element and the element can not be smaller than 0.5㎛.

In addition, since at least two or more elements are required to construct a diffractive pixel using such elements, there is a limit in miniaturization of the device.

Accordingly, the present invention has been made to solve the above problems, by using the optical path difference to generate the optical path difference in the separated light after separating the incident light to cause constructive or destructive interference in the target object. It is an object of the present invention to provide an optical modulator.

The present invention for achieving the above object, the beam splitter for splitting out the light emitted from the light source, and for receiving the reflected light to enter the target object; A driving pixel array for reflecting the light incident from the beam splitter to the beam splitter by varying the length of the optical path using a plurality of pixels driven up and down; Reflecting means for reflecting light incident from the beam splitter to the beam splitter, the light path difference being due to the reflected light reflected from the corresponding pixel of the driving pixel array and the reflecting means corresponding thereto. Constructive or destructive interference occurs.

In addition, the present invention comprises a polarization separator for separating the light emitted from the light source into two polarized light incident in different directions and for injecting each of the reflected light to the target object; A driving pixel array for reflecting the light incident from the polarization separator to the polarization separator by varying the length of the optical path using a plurality of pixels driven up and down; A first polarization converter positioned between the polarization separator and the driving pixel array to convert polarized light incident from the driving pixel array to be output to the polarization separator; A second polarization converter positioned between the first polarization separator and the reflecting means to convert the polarized light incident from the reflecting means and exit to the polarization separator; And reflecting means for reflecting the polarized light incident from the polarized light splitter to the polarized light splitter, wherein the optical path difference between the reflected polarized light reflected from the corresponding pixel of the driving pixel array and the reflected polarized light reflected from the corresponding reflecting means Constructive or destructive interference occurs.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIG. 5A.

5A is a structural diagram of an optical modulator using an optical path difference according to an embodiment of the present invention.

Referring to FIG. 5A, an optical modulator using an optical path difference according to an embodiment of the present invention includes a light source 500, a driving pixel array 510, a beam splitter 520, and a fixed mirror 530. .

The light source 500 is composed of one light emitting source composed of a laser diode having a predetermined wavelength, and the light emitted from the light source 500 is incident to the beam splitter 520.

The beam splitter 520 divides the beam incident from the light source 500 and enters the divided beam into the driving pixel array 510 and the fixed mirror 530, respectively.

The driving pixel array 510 has a mirror surface, and is composed of a plurality of driving pixels 510a to 510e for driving up and down, and reflects incident light.

The fixed mirror 530 has a mirror surface and reflects incident light while being fixed.

Referring to FIG. 5A, the operation of an optical modulator using an optical path difference according to an embodiment of the present invention will be described below.

The light emitted from the light source 500 is incident to the beam splitter 520, and the beam splitter 520 splits the incident light into part of the split light and enters the driving pixel array 510. Another part is incident on the fixed mirror 530.

Then, each driving pixel 510a to 510e of the driving pixel array 510 reflects the incident light back to the beam splitter 520. In addition, the fixed mirror 530 reflects the incident light back to the beam splitter 520.

The beam splitter 520 enters the light reflected from the driving pixel array 510 and the light reflected from the fixed mirror 530 toward the target object (not shown).

At this time, when comparing the light reflected from the driving pixel array 510 and the light reflected from the fixed mirror 530, if the optical path difference has a phase difference by an odd multiple of λ / 2, a destructive interference occurs to the target object 540. When a dark image is formed and the phase difference is set by an even multiple of λ / 2, constructive interference occurs to form a bright image on the object 540.

That is, in the drawing, the light incident after passing through a to b of the driving pixel 510c is reflected and returned to a again, and the even number of lambda / 2 reflected after entering to the fixed mirror 530 c after a and returns to a If the phase difference is as much as twice, constructive interference occurs to form a bright image.

In the drawing, after passing through a 'and entering the driving pixel 510b of b', the light is reflected and returned back to a 'and passes through a' and then enters the fixed mirror 530 c 'and then reflects back to a'. When the phase difference is as much as an odd multiple of λ / 2 returned, destructive interference occurs to form a dark image.

At this time, undesired light generation due to diffraction interference between pixels 510a to 510e is expected. If the phase difference between optical paths ac and ab is (4m + 1) * λ / 6 and the phase difference between optical paths a'-c 'and a'-b' is (2m + 1) * λ / 3, all pixels ( Even when 510a to 510e are driven at intervals, no light is generated.

FIG. 5B is a structural diagram of an optical modulator using an optical path difference according to a second embodiment of the present invention, which is different from the first embodiment in that a second driving pixel array is used instead of a fixed mirror.

5B, the optical modulator using the optical path difference according to the second embodiment of the present invention includes a light source 500, a first driving pixel array 510, a beam splitter 520, and a second driving pixel array ( 530).

The light source 500 is composed of one light emitting source composed of a laser diode having a predetermined wavelength, and the light emitted from the light source 500 is incident to the beam splitter 520.

The beam splitter 520 divides the beam incident from the light source 500 and enters the divided beam into the first driving pixel array 510 and the second driving pixel array 530, respectively.

The first driving pixel array 510 and the second driving pixel array 530 are mirrored on the surface, and are composed of a plurality of driving pixels 510a to 510e and 530a to 530e which are driven up and down, and reflect incident light. do.

Referring to FIG. 5B, the operation of the optical modulator using the optical path difference according to the second embodiment of the present invention will be described below.

The light emitted from the light source 500 is incident to the beam splitter 520, and the beam splitter 520 splits the incident light so that some of the split light is incident to the first driving pixel array 510 and is split. Another portion of the received light is incident on the second driving pixel array 530.

Then, each driving pixel 510a to 510e of the first driving pixel array 510 reflects the incident light back to the beam splitter 520. In addition, the second driving pixel array 530 reflects the incident light back to the beam splitter 520.

The beam splitter 520 enters the light reflected from the first driving pixel array 510 and the light reflected from the second driving pixel array 530 toward a target object (not shown).

In this case, when the light reflected from the first driving pixel array 510 and the light reflected from the second driving pixel array 530 are compared with each other, when the optical path difference has a phase difference by an odd multiple of lambda / 2, an object interference occurs. When a dark image forms on the object 540 and the phase difference is increased by an even multiple of λ / 2, a destructive interference occurs to form a bright image on the object 540.

That is, in the figure, the light incident after passing through a to the first driving pixel 510c of b is reflected and returned to a again, and after passing through a to the second driving pixel 530c c, is reflected and returned to a λ If the phase difference is an even multiple of / 2, constructive interference occurs to form a bright image.

In the drawing, after passing through a 'and entering the first driving pixel 510b of b', the light is reflected and returned back to a 'and then passes through a' and then enters the second driving pixel 530b c '. When the phase difference is set to an odd multiple of λ / 2, which is returned to a ', an offset interference occurs to form a dark image.

 At this time, undesired light generation due to diffraction interference between pixels 510a to 510e is expected. If the phase difference between optical paths ac and ab is (4m + 1) * λ / 6 and the phase difference between optical paths a'-c 'and a'-b' is (2m + 1) * λ / 3, all pixels ( Even when 510a to 510e are driven at intervals, no light is generated.

6 is a structural diagram of an optical modulator using an optical path difference according to a third exemplary embodiment of the present invention.

Referring to the drawings, the optical modulator using the optical path difference according to the third embodiment of the present invention is a light source 600, a driving pixel array 610, a polarization separator 620 that is a grid polarizer (GP), fixed A mirror 630, a target object 640, and first and second polarization transducers 650a and 650b are provided.

The light source 600 is composed of one light emitting source composed of a laser diode having a predetermined wavelength, and the light emitted from the light source 600 is incident to the polarization separator 620.

Polarization separator 620 is a lattice polarizer of the type sold by MOXTEX of Orem, Utah under the trademark PROFLUX.

Compared with a cube-shaped polarizing beam splitter, which may be used but not so desirable, the grating polarizer has a high overall efficiency, a low sensitivity to the angle of incidence, which allows better handling of the meandering rays that are always present in the expanding source even when the grating polarizer is collimated. Low sensitivity; High polarization purity of both channels, which increases throughput as well as increasing conversion efficiency and contrast; There are many advantages, such as having a low cost.

In addition to the cube-shaped polarizing beam splitter and the lattice polarizer, the polarization splitting function can be performed by a polarizing splitter prism using, for example, a poster prism or other birefringent crystals.

The polarization separator 620 transmits the light incident from the light source 600 into P polarization and S polarization while rotating the P polarization by 90 °, for example, and polarizing the S polarization into the driving pixel array 610. , P-polarized light is incident on the fixed mirror 630.

The driving pixel array 610 has a mirror surface, and is composed of a plurality of driving pixels 610a to 610e for driving up and down, and reflects incident polarized light.                     

The fixed mirror 630 has a mirror surface and reflects incident polarized light while being fixed.

The first and second polarization transducers 650a and 650b may include, for example, half-wave plates, and change incident polarized light, for example, converting S polarization into P polarization and P polarization into S polarization. . Suitable first and second polarization transducers 650a and 650b include half-wave faces and prismatic polarizers.

Now, with reference to Figure 6 will be described in detail the operation of the optical modulator using the optical path difference according to an embodiment of the present invention.

The light emitted from the light source 600 is incident to the polarization separator 620, and the polarization separator 620 splits the incident light into one of the divided lights. For example, the S polarized light is incident on the driving pixel array 610 and the divided light is emitted. In another example, P polarized light is incident on the fixed mirror 630.

Each of the driving pixels 610a to 610e of the driving pixel array 610 reflects the incident S-polarized light back to the polarization separator 620. In addition, the fixed mirror 630 reflects the incident polarization back to the polarization separator 620.

In this case, a first polarization transducer 650a is positioned between the driving pixel array 610 and the polarization separator 620, and the first polarization transducer 650a converts the polarized light reflected from the driving pixel array 610 as an example. The S-polarized light is converted into P-polarized light and incident to the polarization separator 620.

In addition, a second polarization transducer 650b is positioned between the fixed mirror 630 and the polarization splitter 620, and the second polarization transducer 650b converts the polarized light reflected from the fixed mirror 630 to P polarized light. Is converted into S-polarized light and incident to the polarization separator 620.

Then, the polarization separator 620 enters the light reflected from the driving pixel array 610 and the same polarized light reflected from the fixed mirror 630 toward the target object 640.

At this time, when comparing the polarization reflected from the driving pixel array 610 and the polarization reflected from the fixed mirror 630, if the optical path difference has a phase difference by an odd multiple of λ / 2, destructive interference occurs to the target object 640. When a dark image is formed and the phase difference is set by an even multiple of λ / 2, destructive interference occurs to form a bright image on the object 640.

That is, in the drawing, the light incident after passing through a to the driving pixel 610c of b is reflected and returned to a again, and the odd number of lambda / 2 reflected after entering to the fixed mirror 630 c after a and returns to a If the phase difference is as much as twice, offset interference occurs to form a dark image.

In the drawing, after passing through a 'and entering the driving pixel 610b of b', the light is reflected and returned back to a 'and passes through a' and then enters the fixed mirror 630 c 'and then reflects back to a'. If the phase difference is equal to the multiple of λ / 2 returned, constructive interference occurs to form a dark phase.

 At this time, undesired light generation is expected due to diffraction interference between the pixels 610a to 610e. For example, in order to reduce interference due to diffraction between the pixels 610a to 610e, the displacement difference between b and b 'is set to be λ / 16. If the phase difference between optical paths ac and ab is (4m + 1) * λ / 6 and the phase difference between optical paths a'-c 'and a'-b' is (2m + 1) * λ / 3, all pixels ( Even when 610a to 610e are driven every other week, no glare occurs.

Although the fixed mirror 630 has been described herein, an optical modulator using an optical path difference may be implemented by using another driving pixel array as in the second embodiment.

7A through 7C are structural diagrams of thin film piezoelectric elements used as the driving pixel arrays of FIGS. 5A, 5B, and 6.

7A is a diagram illustrating a piezoelectric thin film diffraction optical modulator according to a first embodiment. Referring to the drawings, a silicon substrate 701a and a plurality of elements 710a1 to 710an are formed.

The substrate 701a includes depressions to provide air space to the elements 710a1 to 710an, and end portions of the plurality of elements 710a1 to 710an are attached to both sides of the depressions.

The elements 710a1 to 710an have a rod shape, and the bottom surfaces of both ends are attached to both side regions outside the recessed portion of the substrate 701a so that the center portion is spaced apart from the recessed portion of the substrate 701a. The layer 715a is stacked on top, and the portion located in the depression of the substrate 701a includes a lower support 711a that is movable up and down.

In addition, the element 710a is stacked on the lower support 711a, and is stacked on the lower electrode layer 712a and the lower electrode layer 712a for providing a piezoelectric voltage, and contracts and expands when a voltage is applied to both surfaces. It is stacked on the piezoelectric material layer 713a for generating the driving force, on the piezoelectric material layer 713a, and on the upper electrode layer 714a for providing the piezoelectric voltage to the piezoelectric material layer 713a, and on the upper electrode layer 714a. It includes a micro mirror layer 715a for reflecting and diffracting the incident beam.

7B is a diagram illustrating a thin film piezoelectric diffraction optical modulator according to a second embodiment. Referring to the drawings, the first embodiment and the second embodiment are different from each other in that the second embodiment includes piezoelectric layers on both sides. It consists of a substrate 701b and a plurality of elements 710b1 to 710bn.

The substrate 701b has depressions to provide air space to the elements 710b1 to 710bn, and end portions of the plurality of elements 710b1 to 710bn are attached to both sides of the depressions.

The substrate 701b has depressions to provide air spaces to the plurality of elements 710b1 to 710bn, and end portions of the elements 710b1 to 710bn are attached to both sides of the depressions.

The elements 710b1 to 710bn have a rod shape, and lower surfaces of both ends are attached to both side regions outside the recessed portion of the substrate 701b so that the center portion is spaced apart from the recessed portion of the substrate 701b. The portion located in the depression of 701b includes a lower support 711b that is movable up and down.

In addition, the elements 710b1 to 710bn are stacked on the left end of the lower support 711b, and are stacked on the lower electrode layer 712b and the lower electrode layer 712b for providing a piezoelectric voltage. A piezoelectric material layer 713b that contracts and expands to generate a vertical driving force, and an upper electrode layer 714b that is stacked on the piezoelectric material layer 713b and provides a piezoelectric voltage to the piezoelectric material layer 713b.

In addition, the elements 710b1 to 710bn are stacked on the right end of the lower support 711b, and are stacked on the lower electrode layer 712b 'and the lower electrode layer 712b' for providing a piezoelectric voltage. When applied, a piezoelectric material layer 713b 'that contracts and expands to generate a vertical driving force, and an upper electrode layer 714b' that is stacked on the piezoelectric material layer 713b 'and provides a piezoelectric voltage to the piezoelectric material layer 713b'. It includes.

FIG. 7C is a diagram illustrating a thin film piezoelectric diffraction optical modulator according to a third embodiment. Referring to the drawings, a piezoelectric layer is present in a central portion of the third embodiment compared to the first and second embodiments. A silicon substrate 701c and a plurality of elements 710c1 to 710cn are formed.

The substrate 701c has depressions to provide air space to the elements 710c1 to 710cn, and end portions of the elements 710c1 to 710cn are attached to both sides of the depressions.

The elements 710c1 to 710cn have a rod shape, and the bottom surfaces of both ends are attached to both side regions outside the recessed portion of the substrate 701c so that the center portion is spaced apart from the recessed portion of the substrate 701c. The layer 715c is stacked on top of the depressions (parts away from the depressions have been etched away) and includes a lower support 711c that is capable of moving up and down the portions located in the depressions of the substrate 701c.

In addition, the elements 710c1 to 710cn include a lower electrode layer 712c and a lower electrode layer 712c for providing a piezoelectric voltage stacked on the lower support 711c of the upper portion of the recessed portion (the portion out of the recess is etched away). ) Is laminated on the piezoelectric material layer 713c and the piezoelectric material layer 713c, which contracts and expands to generate vertical driving force when voltage is applied to both surfaces thereof, and provides a piezoelectric voltage to the piezoelectric material layer 713c. An upper electrode layer 714c and a micro mirror layer 715c stacked on the upper electrode layer 714c and reflecting and diffracting an incident beam are included.

Here, the depression type of the thin film piezoelectric diffraction type optical modulator has been described as an example. However, the "thin film piezoelectric optical modulator and its manufacturing method" of P2003-077389 discloses a protruding thin film piezoelectric optical modulator, which is also a driving pixel of the present invention. Can be used as an array.

8A through 8D are structural diagrams of the thick film piezoelectric elements of the driving pixel arrays of FIGS. 5A, 5B, and 6.

FIG. 8A illustrates a thick-film actuated cell having a longitudinal length longer than a horizontal length. As shown in FIG. 8A, a lower electrode 821 formed on a predetermined substrate 810 and A piezoelectric / distortion layer 822 formed on the lower electrode 821 and an upper electrode 823 formed on the piezoelectric / distortion layer 822 and vertically driven by a driving power source applied from the outside. And a thick actuating actuating cell 820 whose length in the direction is longer than the length in the horizontal direction.

FIG. 8B is a view showing a thick-film actuating cell having a transverse length greater than a length in a longitudinal direction. As shown in FIG. 8B, a thick-film actuator having a transverse length longer than a length in a vertical direction is shown. It can also be configured to include a cell 820.                     

8C and 8D, the optical modulator further includes a micromirror 824 for maximizing the reflection efficiency of incident light incident on the upper electrode 823 operating as the reflective surface. can do.

As described above, the present invention is not driven by the diffraction interference of the ribbon in the pixel, so that one ribbon constitutes one pixel, thereby reducing the size of the optical device to 1/2 to 1/6.

In addition, the present invention, as described above, because one ribbon constitutes one pixel, the size of the optical device can be reduced, thereby reducing the size of the optical component.

What has been described above is only one embodiment for implementing the optical modulator using the optical path difference according to the present invention, the present invention is not limited to the above-described embodiment, as claimed in the following claims Without departing from the gist of the invention, anyone of ordinary skill in the art to which the present invention will have the technical spirit of the present invention to the extent that various modifications can be made.

Claims (15)

A beam splitter for dividing and exiting the light emitted from the light source, and for receiving the reflected light to enter the target object; A drive pixel array configured to reflect the light path from the beam splitter to the beam splitter by varying the length of the light path using a plurality of drive pixels driven up and down; And Reflecting means for reflecting light incident from the beam splitter to the beam splitter, Constructive or destructive interference occurs due to the optical path difference between the reflected light reflected from the corresponding drive pixel of the drive pixel array and the reflected light reflected from the reflecting means corresponding thereto; The driving pixel of the driving pixel array includes a substrate and a piezoelectric material layer which is supported by the substrate and spaced apart from the substrate to secure a driving space, and is moved away from or close to the substrate when voltage is applied to both sides. Light modulator using the optical path difference, characterized in that comprises an element to make. delete delete delete A beam splitter for dividing and exiting the light emitted from the light source, and for receiving the reflected light to enter the target object; A drive pixel array configured to reflect the light path from the beam splitter to the beam splitter by varying the length of the light path using a plurality of drive pixels driven up and down; And Reflecting means for reflecting light incident from the beam splitter to the beam splitter, Constructive or destructive interference occurs due to the optical path difference between the reflected light reflected from the corresponding drive pixel of the drive pixel array and the reflected light reflected from the reflecting means corresponding thereto; The driving pixel of the driving pixel array reflects incident light by having a substrate and a piezoelectric material layer stacked on the substrate and having a voltage applied to both sides thereof so as to contract and expand so that an externally exposed reflective surface moves away from or close to the substrate. Light modulator using the optical path difference, characterized in that comprises an element to make. The method according to claim 1 or 5, The optical modulator using the optical path difference, characterized in that the reflecting means is a fixed mirror. The method according to claim 1 or 5, And the reflecting means is a driving pixel array. A polarization separator for splitting the light emitted from the light source into two polarized light and incident light in different directions, and for injecting the reflected light into the target object; A driving pixel array configured to reflect the light incident from the polarization separator to the polarization separator by varying the length of the optical path using a plurality of pixels driven up and down; A first polarization converter positioned between the polarization separator and the driving pixel array to convert polarized light incident from the driving pixel array to be output to the polarization separator; Reflecting means for reflecting the polarized light incident from the polarized light separator to the polarized light separator; And A second polarization converter positioned between the polarization separator and the reflection means to convert the polarized light incident from the reflection means and exit to the polarization separator, And a constructive or destructive interference occurs due to the optical path difference between the reflected polarized light reflected from the pixel of the driving pixel array and the reflected polarized light reflected from the reflecting means corresponding thereto. The method of claim 8, The polarization separator is a light modulator using a light path difference, characterized in that the lattice polarizer. The method of claim 8, And the driving pixel array is a reflective optical modulator. The method of claim 8, And the driving pixel array is a diffraction type optical modulator. The method of claim 11, And the driving pixel array is a thin film piezoelectric diffraction type optical modulator. The method of claim 11, And the driving pixel array is a thick film piezoelectric diffraction type optical modulator. The method according to any one of claims 8 to 13, The optical modulator using the optical path difference, characterized in that the reflecting means is a fixed mirror. The method according to any one of claims 8 to 13, And the reflecting means is a driving pixel array.

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