# US 8,541,713 B1 · Subsurface glass reticles > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,541,713 B1 - Document ID: US8541713B1 - Status: Granted - Kind: B1 - Application number: 12/707,638 - Filed: 2010-02-17 - Granted: 2013-09-24 - Earliest claimed: 2010-02-17 - Assignees: Translume, Inc. - Applicants: Mark A. Dugan; Ali Said - Inventors: Mark A. Dugan; Ali Said - Web page: https://patentgrep.com/patent/US8541713B1 ## CPC - G02B 23/14: Viewfinders (for photographic apparatus G03B13/02) - B23K 26/0006: {taking account of the properties of the material involved (B23K26/32, B23K26/40 take precedence)} - B23K 26/53: for modifying or reforming the material inside the workpiece, e.g. for producing break initiation cracks - F41G 1/00: Sighting devices ({structurally associated with laser telemeters F41G3/065;} for indirect laying of fire F41G3/16; bombsights F41G3/24) - F41G 3/06: with rangefinder (rangefinders per se G01C) - B23K 2103/50: {Inorganic materials other than metals or composite materials} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - F41G: WEAPON SIGHTS; AIMING (optical aspects thereof G02B) ## Abstract An optical instrument for light incoming along a principal optical axis includes a glass block and a subsurface object within the glass block. The subsurface object includes an arrangement of object marks. Each object mark includes a plurality of scattering layers stacked against the principal optical axis of the incoming light. First and second scattering layers of the plurality of scattering layers have different polarization responses. ## Claims ### Claim 1 A method of fabricating a reticle for a telescopic sight, the method comprising the steps of: directing ultrashort laser pulses toward a glass block; and forming a subsurface object within the glass block, the subsurface object having a plurality of intrinsic scattering layers; wherein the forming step includes selecting a polarization state of the ultrashort laser pulses to vary a polarization dependence of the subsurface object over the plurality of intrinsic scattering layers; and wherein the forming step includes writing a first intrinsic scattering layer of the plurality of intrinsic scattering layers within the glass block with the ultrashort laser pulses in a first polarization state, and writing a second intrinsic scattering layer of the plurality of intrinsic scattering layers within the glass block with the ultrashort laser pulses in a second polarization state. ### Claim 2 (depends on 1) The method of claim 1, wherein the ultrashort laser pulses are configured to cause a change in refractive index of the glass block. ### Claim 3 (depends on 1) The method of claim 1, wherein the ultrashort laser pulses are configured to form a void in the glass block. ### Claim 4 (depends on 1) The method of claim 1, wherein the subsurface object is disposed along a non-flat surface within the glass block. ### Claim 5 (depends on 1) The method of claim 1, further comprising: integrating a light source into the telescope sight for side illumination of the reticle; and forming a further intrinsic scattering layer within the glass block to redirect the side illumination. ### Claim 6 (depends on 5) The method of claim 5, wherein the further scattering layer has a spatially defined pattern that corresponds with a pattern of the subsurface object. ### Claim 7 (depends on 1) The method of claim 1, wherein the plurality of intrinsic scattering layers are arranged in a stack and contiguous with one another. ### Claim 8 (depends on 1) The method of claim 1, wherein the plurality of intrinsic scattering layers are arranged in a stack and spaced from one another. ### Claim 9 (depends on 1) The method of claim 1, further comprising forming an array of intrinsic waveguides within the glass block, the array of intrinsic waveguides being configured to diffuse any light not scattered by the plurality of intrinsic scattering layers. ### Claim 10 A method of fabricating a reticle for a telescopic sight, the method comprising the steps of: directing ultrashort laser pulses toward a glass block; and forming a subsurface object within the glass block, the subsurface object having a plurality of intrinsic scattering layers; wherein the forming step includes selecting a polarization state of the ultrashort laser pulses to vary a polarization dependence of the subsurface object over the plurality of intrinsic scattering layers; and wherein the forming step includes writing a set of parallel tracks within each intrinsic scattering layer, and varying the polarization state of the ultrashort laser while writing each track. ### Claim 11 (depends on 10) The method of claim 10, wherein the ultrashort laser pulses are configured to cause a change in refractive index of the glass block. ### Claim 12 (depends on 10) The method of claim 10, wherein the ultrashort laser pulses are configured to form a void in the glass block. ### Claim 13 (depends on 10) The method of claim 10, wherein the subsurface object is disposed along a non-flat surface within the glass block. ### Claim 14 (depends on 10) The method of claim 10, further comprising: integrating a light source into the telescope sight for side illumination of the reticle; and forming a further intrinsic scattering layer within the glass block to redirect the side illumination. ### Claim 15 (depends on 14) The method of claim 14, wherein the further scattering layer has a spatially defined pattern that corresponds with a pattern of the subsurface object. ### Claim 16 (depends on 10) The method of claim 10, wherein the polarization state is varied in a continuous manner. ### Claim 17 (depends on 10) The method of claim 10, wherein the polarization state is varied in discrete steps. ### Claim 18 (depends on 10) The method of claim 10, wherein the polarization state is varied randomly. ### Claim 19 (depends on 10) The method of claim 10, wherein writing the set of parallel tracks comprises introducing a discontinuity along a length of at least one track of the set of parallel tracks. ### Claim 20 (depends on 10) The method of claim 10, wherein adjacent tracks in the set of parallel tracks are spaced apart from one another by about 0.5 microns to about 1.5 microns.