US-20260126599-A1 - COOPERATION BETWEEN LASER AND OPTICAL FIBER

US20260126599A1US 20260126599 A1US20260126599 A1US 20260126599A1US-20260126599-A1

Abstract

An article of manufacture including a fiber optic termination of a small core optical fiber for use with a surgical laser apparatus (the output from which may, in a specific case, be characterized by a high M 2 factor) or other high-power or high-energy laser (including an appropriate fiber laser) is configured for safe and efficient coupling of light at a large laser focal point and/or to enable the process of coupling of radiant intensities exceeding the silica fiber damage thresholds and/or those ionizing the air if fully focused therein. The termination may include a glass cylinder structured to include a core region and a glass cladding region the ratio of dimensions of which is substantially equal to the ratio of respectively-corresponding dimensions of the employed optical fiber. A method of propagating light through such article of manufacture.

Inventors

Stephen E. Griffin

Assignees

CYCLONE BIOSCIENCES, LLC

Dates

Publication Date: 20260507
Application Date: 20251231

Claims (20)

1 . An article of manufacture having an axis and comprising: an optical fiber component; and an intermediate body of a glass material axially attached to the optical fiber component at a first end thereof; wherein the optical fiber component includes: two first optical fiber elements each having a first glass content of a first glass medium, each of the two first optical fiber element carrying a corresponding group of multiple dielectric boundaries extending across the axis, and a second optical fiber element having a second glass content of a second glass medium, the second glass content being different from the first glass content.
2 . An article of manufacture according to claim 1 , wherein the intermediate body includes a passive optical taper.
3 . An article of manufacture according to claim 1 , further comprising a substantially cylindrical body of glass seamlessly and substantially coaxially attached to a second end of the intermediate body, wherein every diameter of multiple diameters of the intermediate body is different from both a diameter of the optical fiber component and a diameter of the substantially cylindrical body.
4 . An article of manufacture according to claim 3 , wherein at least one of the substantially cylindrical body and the intermediate body does not contain doped glass.
5 . An article of manufacture according to claim 1 , wherein the intermediate body is dimensioned to define an angle of divergence of an optical mode of the optical fiber component propagating through the intermediate to have a first value at the first end and a second value a location within the intermediate body away from the first end, the first value being larger than the second value, or wherein the intermediate body is dimensioned to change the angle of divergence of the optical mode of the optical fiber component, propagating therethrough from the optical fiber component, at least once.
6 . An article of manufacture according to claim 1 , wherein a combination of the two first optical fiber elements and the second optical fiber element is configured to increase an irradiance of light, generated in said second optical fiber element when an auxiliary light is delivered to the second optical fiber element.
7 . An article of manufacture according to claim 1 , wherein the second optical fiber element is separated from the intermediate body by a first optical fiber element of the two first optical fiber elements.
8 . A method comprising: using the article of manufacture according to claim 1 : at least partially transmitting first light through a first optical fiber element, of the two optical fiber elements, and transmitting said first light through the second optical fiber element to form operationally useful light at an end of the optical fiber component, wherein the at least partially transmitting the first light through said first optical fiber element includes partially transmitting the first light through first multiple regions of the first glass medium, said first multiple regions being separated from one another axially and having substantially refractive indices; and propagating the operationally useful light through the intermediate body to define an output light at an output facet of the article of manufacture.
9 . A method according to claim 8 , further comprising transmitting the operationally useful light through a substantially cylindrical body of glass axially connected to an end of the intermediate body.
10 . A method according to claim 8 , further comprising multiply circulating the first light between a first group of the multiple dielectric boundaries in a first region of the first glass medium and a second group of the multiple dielectric boundaries in a second region of said first glass medium.
11 . A method according to claim 8 , wherein at least one of the following conditions is satisfied: (a) wherein said propagating includes delivering the operationally useful light from a chosen location of a first optical fiber element of the two first optical fiber elements to the output facet of the article of manufacture un-interruptingly through a body of a glass material dimensioned to have an outer surface that is differentiable; (b) wherein said propagating includes delivering the operationally useful light from the chosen location to said output facet un-interruptingly through a glass material dimensioned to have an outer surface that includes a sequence of conical surfaces, wherein a first conical surface at an entrance of the substantially cylindrical portion has a first apex angle and a second conical surface separated from the output facet by the first conical surface has a second apex angle, the second apex angle being smaller than the first apex angle; (c) wherein said propagating includes delivering said operationally useful light from the chosen location to the output facet through a sequence of multiple coaxially positioned truncated cones of glass material spatially coordinated such that a top of one truncated cone forms at least a part of a base of another truncated cone.
12 . A method comprising: partially transmitting first light completely within an optical fiber that includes a first glass medium containing multiple immediately-neighboring one another dielectric boundaries defined across an axis of the first glass medium through at least two of said multiple immediately-neighboring one another dielectric boundaries in a first region of said first glass medium to form operationally useful light, and propagating said operationally useful light only in one direction through a substantially cylindrical portion of an optical termination element connected to the first glass medium while expanding a size of a spatial distribution of said operationally useful light upon such propagating to define an output light at a distal end of said substantially cylindrical portion.
13 . A method according to claim 12 , wherein said partially transmitting first light within a first glass medium includes partially transmitting first light within the optical fiber that includes two first optical fiber elements and a second optical fiber element between said two first optical fiber elements, wherein each of the two first optical fiber elements has a first glass content, wherein a second glass content of the second optical fiber element is different from the first glass content.
14 . A method according to claim 13 , wherein each of the two first optical fiber elements carries a corresponding group of said multiple immediately-neighboring dielectric boundaries defined across the axis.
15 . A method according to claim 12 , further comprising channeling the operationally useful light from the at least two immediately-neighboring dielectric boundaries to the substantially cylindrical portion completely within a connecting glass medium while maintaining said size substantially constant during said channeling.
16 . A method according to claim 12 , wherein each of the at least two immediately-neighboring dielectric boundaries in the first region separates corresponding areas of said first glass medium that have different refractive indices.
17 . A method according to claim 12 , further comprising multiply circulating the first light between at least two dielectric boundaries of said multiple immediately-neighboring one another dielectric boundaries in the first region and at least two dielectric boundaries multiple immediately-neighboring one another dielectric boundaries in a second region of said first glass medium.
18 . A method according to claim 17 , wherein said multiply circulating includes multiply transmitting the first light within an intermediate glass medium axially separating the first and second regions of the first glass medium while coupling second light into the intermediate glass medium.
19 . A method according to claim 12 , further comprising delivering said operationally useful light from the optical fiber to the distal end through a section of glass material with an outer diameter that is different from each of an outer diameter of the optical fiber and from an outer diameter of the substantially cylindrical portion.
20 . A method according to claim 19 , comprising: (a) delivering the operationally useful light from the optical fiber to said distal end un-interruptingly through a glass material dimensioned to have an outer surface that is differentiable, and/or (b) delivering said operationally useful light from the optical fiber said distal end un-interruptingly through a glass material dimensioned to have an outer surface that includes a sequence of conical surfaces, wherein a first conical surface at an entrance of the substantially cylindrical portion has a first apex angle and a second conical surface separated from the substantially cylindrical portion by the first conical surface has a second apex angle, the second apex angle being larger than the first apex angle; and/or (c) delivering said operationally useful light from the optical fiber said distal end through a sequence of multiple coaxially positioned truncated cones of glass material, wherein said multiple truncated cones are spatially coordinated such that a top of one truncated cone forms a part of a base of another truncated cone.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This patent application is a continuation of U.S. patent application Ser. No. 19/242,472 filed Jun. 18, 2025 and now published as US 2025/0314838, which is a continuation of U.S. patent application Ser. No. 18/768,515 filed Jul. 10, 2024 and now granted as U.S. Pat. No. 12,372,730, which is a continuation-in part of U.S. patent application Ser. No. 17/994,517 filed Nov. 28, 2022 and now granted as U.S. Pat. No. 12,068,573, which is continuation-in-part of U.S. patent application Ser. No. 17/847,608 filed Jun. 23, 2022 and now granted as U.S. Pat. No. 12,222,564, which in turn claims priority from and benefit of the US Provisional Ser. No. 63/225,812 filed Jul. 26, 2021. The disclosure of each of the above-identified applications is incorporated by reference herein. TECHNICAL FIELD This invention relates to fiber-optic termination arrangements configured to radiatively couple optical waveguides such as optical fibers and sources of laser radiation—for example, surgical lasers (e.g., holmium lasers, CTH:YAG, and Ho:YAG lasers, for example) and/or other laser sources generating low-M2 (low beam quality factor) laser output such as to efficiently couple such low-quality but high intensity radiant output into the optical fibers and/or fiber lasers and/or fiber amplifiers. The discussed terminations may at least in some circumstances facilitate coupling of high-energy laser pulses to optical fibers with such core diameters that otherwise require exceeding the breakdown threshold level for ambient air or the damage threshold of the fiber-optical surface (in which case, the use of the embodiments of the invention avoids and/or prevent such breakdown) and/or simplify the process of fabrication substantially eliminate the need in mutual alignment/orientation of constituent component to produce compact integrated optical arrangements that are substantially not subject to breakage during intended use. RELATED ART Holmium lasers primarily find application in urology and, specifically, for vaporization and enucleation of hyperplastic prostate tissue (BPH) and breaking apart kidney stones (although additional applications exist for both soft and hard tissue targets). These infrared lasers typically produce 0.2 Joule to 6 Joule pulses with 350μs to 1200 μs pulse width at rates from about 5 pulses per second (pps) to about 120 pps at wavelengths ranging from about 2.08 μm to about 2.14 μm, with average powers ranging from about 8 W to about 140 W. A skilled person understands that light outputs generated by holmium lasers are spatially multimode and of particularly low quality, which is reflected in a low M2 factor or parameter. (The M2 factor of a laser beam also referred to as a beam quality factor or beam propagation factor, is a common measure of the beam quality of a laser beam and is known in related art to represent the degree to which the light beam can be focused for a given beam divergence angle. A diffraction-limited beam such as a Gaussian beam, for example, has an M2 factor of 1. A typical value of M2 for a surgical laser such as a holmium laser is at least several tens, sometimes less than 50, but when such laser is overheated—which is a common occurrence—the M2 value can reach triple digits: thermally-induced refractive index gradients and birefringence in holmium laser rods distort the laser output, both beam diameter and divergence drift during use/operation of a given laser, and myriad spatial modes are generated.) Higher-power holmium lasers employ two or more laser heads the outputs from which are combined to produce the total laser output, which further reduces the beam quality. Furthermore, surgical lasers are routinely repositioned and subjected to jolts and bumps in hospital corridors, freight elevators, thresholds, etc., which detrimentally affects the degree of adjustment of constituent parts of the lasers: this leads to the need to keep the corresponding focusing optics as robust and simple as possible. Structurally simple optics, used in combination with poor quality laser power output, produce focal spots that are atypically large, misshapen, unstable, and vary widely in parameters not only from manufacturer to manufacturer but even throughout a given laser's lifetime and even within a single surgical session. (Indeed, nominal laser focal spot diameters are often defined at a 1/e2-level of maximum of a semi-Gaussian irradiance profile, such that about 14% of the laser output energy lies outside of the nominal spot diameter. Pulses produced at the beginning of a given session—that is, from cold laser media—typically have higher energy than subsequent pulses, but as the laser medium heats with use the pulse foci balloon and may drift.) High-energy infrared laser pulses vaporize most of the materials (from polymers to metals) that are used in producing fiber-optic coupling structures devised to have such light pulses coupled to the optical fibers. Optical fib