Beam splitter apparatus and system

• US 7,551,359 B2
• Filed: 09/14/2006
• Issued: 06/23/2009
• Est. Priority Date: 09/14/2006
• Status: Expired due to Fees

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Faklis, Dean, Murnan, Andrew J.
• Primary Examiner(s): Sugarman; Scott J
• Assistant Examiner(s): PINKNEY, DAWAYNE
• Application Number:
  US11/531,870
• Publication Number:
  US 20080068721A1
• Time in Patent Office: 1,013 Days
• Field of Search: 359/629, 359/634, 359636-640, 359/831, 359833-834, 359/669
• US Class Current: 359/629
• CPC Class Codes: G02B 17/04 using prisms only
• CPC Class Codes: G02B 27/106 for splitting or combining a plurality of identical beams or images, e.g. image replication
• CPC Class Codes: G02B 27/143 using macroscopically faceted or segmented reflective surfaces
• CPC Class Codes: G02B 27/144 using partially transparent surfaces without spectral selectivity G02B27/147 takes precedence
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: G02B 5/122 cube corner, trihedral or triple reflector type
• CPC Class Codes: G03F 7/70108 Off-axis setting using a light-guiding element, e.g. diffractive optical elements [DOEs] or light guides
• CPC Class Codes: G03F 7/70375 Multiphoton lithography or multiphoton photopolymerization; Imaging systems comprising means for converting one type of radiation into another type of radiation
• CPC Class Codes: G03F 7/70383 Direct write, i.e. pattern is written directly without the use of a mask by one or multiple beams maskless lithography using a programmable mask G03F7/70291
• CPC Class Codes: G03F 7/7055 Exposure light control in all parts of the microlithographic apparatus, e.g. pulse length control or light interruption

Abstract

A beam splitter apparatus comprises a beam splitter and a plurality of prisms disposed about the beam splitter. The beam splitter apparatus is configured to split an incident laser beam into a plurality of beamlets exhibiting substantially equal energy and traversing substantially equal optical path lengths through the beam splitter apparatus.

Claims

1. A system comprising:

a light source to provide an incident light beam; and

a beam splitter apparatus to split the incident light beam into at least (2ⁿ−

1) beamlets, n being at least 3, wherein the beam splitter apparatus comprises;

a beam splitter; and

(2n−

2) prisms in optical contact with the beam splitter;

wherein the beam splitter is a cube beam splitter comprising;

a first side;

a second side perpendicular to the first side;

a third side perpendicular to the second side; and

a fourth side perpendicular to the first side, and

wherein the (2n−

2) prisms comprises;

a first prism member positioned along the first side of the cube beam splitter;

a second prism member positioned along the second side of the cube beam splitter;

a third prism member positioned along the third side of the cube beam splitter;

a fourth prism member positioned along the fourth side of the cube beam splitter.

2. The system of claim 1, and further comprising:

a fifth prism member positioned along the first side of the cube beam splitter adjacent to the first prism member; and

a sixth prism member positioned along the second side of the cube beam splitter adjacent to the second prism member.

3. A system comprising:

a light source to provide an incident light beam

a beam splitter apparatus to split the incident light beam into at least (2ⁿ−

1) beamlets, n being at least 2, wherein the beam splitter apparatus comprises;

a beam splitter; and

(2n−

2) prisms in optical contact with the beam splitter;

a layer of a multiphoton curable photoreactive composition; and

a focusing lens defining a field of view within the layer, the field of view comprising a plurality of subfields, wherein at least one of the beamlets cures a region of the layer within at least one of the subfields.

4. An apparatus comprising:

a beam splitter configured to split an incident light beam into a first beamlet and a second beamlet;

a first prism member configured to reflect the first beamlet into the beam splitter, wherein the first beamlet traverses the beam splitter and splits into a third beamlet and a fourth beamlet;

a second prism member configured to reflect the second beamlet into the beam splitter, wherein the second beamlet traverses the beam splitter and splits into a fifth and sixth beamlet;

a third prism member configured to reflect the third and fifth beamlets into the beam splitter; and

a fourth prism member configured to reflect the fourth and sixth beamlets into the beam splitter, wherein the first, second, third, and fourth prisms are arranged to achieve a predetermined path difference between the third, fourth, fifth, and sixth beamlets.

5. The apparatus of claim 4, wherein the predetermined path difference is zero.

6. The apparatus of claim 4, wherein the first and second beamlets travel substantially equal path lengths through the first and second prism members, respectively, the third and fifth beamlets each travel an equal path length through the fourth prism member, and the fourth and sixth beamlets each travel an equal path length through the fourth prism member.

7. The apparatus of claim 4, wherein the beam splitter is a cube beam splitter.

8. The apparatus of claim 4, wherein after the third and fifth beamlets exit the third prism member, the third and fifth beamlets traverse the beam splitter, and the third beamlet splits into a seventh and eighth beamlet, the fourth beamlet splits into a ninth and tenth beamlet, and wherein after the fourth and sixth beamlets exit the third prism member, the fourth and sixth beamlets traverse the beam splitter, and the fifth beamlet splits into an eleventh and twelfth beamlet, and the sixth beamlet splits into a thirteenth and fourteenth beamlet.

9. The apparatus of claim 8, and further comprising:

a fifth prism member configured to reflect the seventh, ninth, eleventh, and thirteenth beamlets into the beam splitter, the seventh, ninth, eleventh, and thirteenth beamlets each traveling an equal path length through the fifth prism member; and

a sixth prism member configured to reflect the eighth, tenth, twelfth, and fourteenth beamlets into the beam splitter, the eighth, tenth, twelfth, and fourteenth beamlets each traveling an equal path length through the sixth prism member.

10. The apparatus of claim 4, and further comprising:

a layer of index matching fluid disposed between each of the plurality of prism members and the beam splitter.

11. The apparatus of claim 4, wherein each of the plurality of prism members is selected from a group consisting of:

a cube prism, a pentaprism, and a porroprism.

12. The apparatus of claim 4, and further comprising:

a focusing portion configured to arrange the third, fourth, fifth, and sixth beamlets into an array of beamlets, the array being one of a linear array or a two-dimensional array of beamlets.

13. The apparatus of claim 4, wherein the first and third prism members are separated by a distance calculated according to a first formula:

$Z_n=\underset{n=1}{\overset{S-1}{\sum <br><br>}}<br><br>\frac{n·<br><br>L_z}{2}$

and the second and fourth prism members are separated by a distance calculated according to a second formula;

$X_n=\underset{n=1}{\overset{s-1}{\sum <br><br>}}<br><br>\frac{n·<br><br>L_x}{2}+P·<br><br>2^{\left(n-2\right)}.$

14. The apparatus of claim 4, wherein a first distance between the first and third prism members determines a first pitch between the third and fourth beamlets, and a second distance between the second and fourth prism members determines a second pitch between the fifth and sixth beamlets.

15. The apparatus of claim 14, wherein the first and second pitch are substantially equal.

16. An optical apparatus for splitting an incident light beam into a plurality of beamlets, the optical apparatus comprising:

a first cube beam splitter comprising a first splitter portion;

a second cube beam splitter comprising a second splitter portion;

a third cube beam splitter comprising a third splitter portion;

a first pentaprism disposed between the first and second cube beam splitters;

a second pentaprism disposed between the first and second beam splitters and opposing the first pentaprism;

a third pentaprism disposed between the second and third beam splitters; and

a fourth pentaprism disposed between the second and third beam splitters and opposing the third pentaprism.

17. The optical apparatus of claim 16, wherein the first pentaprism comprises a first apex and the second pentaprism comprises a second apex and the first and second pentaprisms are arranged such that the first apex and the second apex are unaligned.

18. The optical apparatus of claim 16, wherein the first and second pentaprisms are shifted with respect to each other by a distance S₁ and the third and fourth pentaprisms are shifted with respect to each other by a distance S₂, and S₁ and S₂ are in operative relation to a pitch between the plurality of beamlets.

19. A system comprising:

a light source to provide an incident light beam; and

a beam splitter apparatus to split the incident light beam into a plurality of beamlets separated from each other by a pitch P, wherein the beam splitter apparatus comprises;

a beam splitter, wherein the beam splitter splits the incident light beam S number of times;

a first set of prisms disposed along a first axis, wherein each of the prisms of the first set of prisms contacts the beam splitter along dimension L_z and an n^th prism of the first set of prisms is a distance Z_n from a first reference point, where Z_n is calculated according to a first formula;

$Z_n=\underset{n=1}{\overset{S-1}{\sum <br><br>}}<br><br>\frac{n·<br><br>L_z}{2};<br><br>$

 

and

a second set of prisms disposed along a second axis that is orthogonal to the first axis, wherein each of the prisms of the second set of prisms contacts the beam splitter along dimension L_x and an n^th prism of the second set of prisms is a distance X_n from a second reference point, where X_n is calculated according to a second formula;

$X_n=\underset{n=1}{\overset{s-1}{\sum <br><br>}}<br><br>\frac{n·<br><br>L_x}{2}+P·<br><br>2^{\left(n-2\right)}.$

20. The system of claim 19, wherein the beam splitter is a cube beam splitter, and the first reference point is a first side of the cube beam splitter and the second reference point is a second side of the cube beam splitter.

21. The system of claim 19, wherein the each prism of the first and second set of prisms is a corner cube prism.