Single-fiber multi-spot laser probe for ophthalmic endoillumination
View Patent ↗An ophthalmic endoilluminator is provided. The ophthalmic endoilluminator includes a light source, a first optical assembly, an optical coupling element, and an optical fiber having an optical grating located distally on the optical fiber, the optical fiber optically coupled to the optical coupling element. The first optical assembly receives and substantially collimates the white light. The optical coupling element receives the substantially collimated white light from the first optical assembly and directs the light to an optical fiber. The optical grating couples to the distal end of the optical fiber, the optical grating having a surface relief grating, and an overlayer optically coupled to the surface relief grating. The optical grating is operable to substantially diffract incident light into N diffraction orders, the N diffraction orders having a substantially uniform intensity.
1. An ophthalmic endoilluminator comprising:
a light source operable to produce light;
a first optical assembly coupled to the light source, the first optical assembly operable to receive and substantially collimate the light from the light source;
an optical coupling element, the optical coupling element operable to receive the substantially collimated white light from the first optical assembly;
an optical fiber optically coupled to the optical coupling element, the optical fiber operable to conduct the white light into an eye; and
an optical grating coupled to the distal end of the optical fiber, the optical grating comprising:
a surface relief grating; and
an overlayer optically coupled to the surface relief grating, the optical grating operable to substantially diffract incident light into N diffraction orders, the N diffraction orders having a substantially uniform intensity, wherein N is 2 wherein; the overlayer comprises a planar specular distal surface operable to avoid distortion or aberration of N diffraction orders beams as the beams emerge from the overlayer into an ambient medium.
2. The ophthalmic endoilluminator of claim 1 , wherein:
the overlayer comprises a layer of dielectric material.
3. The ophthalmic endoilluminator of claim 1 , wherein:
the optical grating diffracts light into the N diffraction orders having a substantially uniform intensity when the optical grating is immersed in air or saline solution.
4. The ophthalmic endoilluminator of claim 1 , wherein:
a refractive index mismatch exists between a refractive index of the surface relief grating and a refractive index of the overlayer.
5. The ophthalmic endoilluminator of claim 1 , wherein:
the refractive index of the surface relief grating is greater than that of the refractive index of the overlayer.
6. The ophthalmic endoilluminator of claim 1 , wherein:
an amplitude of a depth modulation of the optical grating is determined according to
d
mod
=
d
(
Δ
n
Δ
n
mod
)
where Δn is a refractive index mismatch between a substrate of the surface grating and air, Δn mod is a refractive index mismatch between the substrate of the surface grating and the overlayer, and d is a thickness of the optical grating.
7. The ophthalmic endoilluminator of claim 1 , wherein:
the overlayer is created from curing optical adhesive.
8. An ophthalmic endoilluminator comprising:
a light source operable to produce light;
a first optical assembly coupled to the light source, the first optical assembly operable to receive and substantially collimate the light from the light source;
an optical coupling element, the optical coupling element operable to receive the substantially collimated white light from the first optical assembly;
an optical fiber optically coupled to the optical coupling element, the optical fiber operable to conduct the white light into an eye; and
an optical grating coupled to the distal end of the optical fiber, the optical grating comprising:
a surface relief grating; and
an overlayer optically coupled to the surface relief grating, wherein a refractive index mismatch exists between a refractive index of the surface relief grating and a refractive index of the overlayer, the optical grating operable to substantially diffract incident light into N diffraction orders, the N diffraction orders having a substantially uniform intensity when the optical grating is immersed in air or saline solution, wherein N is 2 wherein; the overlayer comprises a planar specular distal surface operable to avoid distortion or aberration of N diffraction orders beams as the beams emerge from the overlayer into an ambient medium.
9. The ophthalmic endoilluminator of claim 8 , wherein the overlayer comprises a layer of dielectric material.
10. The ophthalmic endoilluminator of claim 8 , wherein:
the refractive index of the surface relief grating is greater than that of the refractive index of the overlayer.
11. The ophthalmic endoilluminator of claim 8 , wherein:
an amplitude of a depth modulation of the optical grating is determined according to:
d
mod
=
d
(
Δ
n
Δ
n
mod
)
where Dn is a refractive index mismatch between a substrate of the surface grating and air, Dn mod is a refractive index mismatch between the substrate of the surface grating and the overlayer, and d is a thickness of the optical grating.
12. The ophthalmic endoilluminator of claim 8 , wherein the overlayer is created from curing optical adhesive.
13. A method comprising:
generating light with a light source;
substantially collimating the light;
optically coupling the white light to at least one optical fiber to produce at least one optical output;
optically coupling the at least one optical output to an ophthalmic endoilluminator fiber with an optical coupling element; and
conducting the optical output with the ophthalmic endoilluminator fiber to illuminate an interior region of an eye, the ophthalmic endoilluminator fiber having an optical grating coupled to the distal end of the ophthalmic endoilluminator fiber, the optical grating operable to substantially diffract incident light into N diffraction orders the N diffraction orders having a substantially uniform intensity when the optical grating is immersed in air or saline solution, wherein N is 2 the optical grating comprising: a surface relief grating; and an overlayer optically coupled to the surface relief grating, wherein: the overlayer comprises a planar specular distal surface operable to avoid distortion or aberration of N diffraction orders beams as the beams emerge from the overlayer into an ambient medium.
14. The method of claim 13 , wherein a refractive index mismatch exists between a refractive index of the surface relief grating and a refractive index of the overlayer.
15. The method of claim 13 , wherein:
an amplitude of a depth modulation of the optical grating is determined according to:
d
mod
=
d
(
Δ
n
Δ
n
mod
)
where Δn is a refractive index mismatch between a substrate of the surface grating and air, Δn mod is a refractive index mismatch between the substrate of the surface grating and the overlayer, and d is a thickness of the optical grating.
16. The method of claim 13 , the overlayer comprises a layer of dielectric material.