Optical endoscope
阅读说明:本技术 光学内窥镜 (Optical endoscope ) 是由 瓦莱里奥·普鲁内里 罗宾·康普豪森 于 2017-11-30 设计创作,主要内容包括:本发明涉及一种光学内窥镜(1),其包括具有近端(3)和远端(4)的光纤元件(2),其中在所述光纤元件(2)的远端(4)上布置有光波导块(6),所述光波导块(6)包括刚性材料,两个或更多个光波导(7)形成于所述刚性材料中。(The invention relates to an optical endoscope (1) comprising an optical fiber element (2) having a proximal end (3) and a distal end (4), wherein an optical waveguide block (6) is arranged on the distal end (4) of the optical fiber element (2), the optical waveguide block (6) comprising a rigid material in which two or more optical waveguides (7) are formed.)
1. An optical endoscope (1) comprising a fiber optic element (2) having a proximal end (3) and a distal end (4), wherein an optical waveguide block (6) is arranged at the distal end (4) of the fiber optic element (2), the optical waveguide block (6) comprising a rigid material in which two or more optical waveguides (7) are formed.
2. The optical endoscope (1) according to claim 1, wherein the two or more optical waveguides (7) are integrally formed with the rigid material of the optical waveguide block (6).
3. The optical endoscope (1) according to claim 1 or 2, wherein the two or more optical waveguides (7) are formed by portions of the rigid material having a higher refractive index than the surrounding portions.
4. The optical endoscope (1) according to any of the preceding claims, wherein the two or more optical waveguides (7) are obtained by ultrafast laser writing.
5. The optical endoscope (1) according to any of the preceding claims, wherein the rigid material is optically transparent at the operating wavelength of the optical endoscope (1).
6. The optical endoscope (1) according to any of the preceding claims, wherein the rigid material comprises glass, polymers and/or semiconductors.
7. The optical endoscope (1) according to any of the preceding claims, wherein each of the two or more optical waveguides (7) comprises an end facing the optical fiber element (2) and arranged in a first surface of the optical waveguide block, the coupling end (8), and an end facing away from the optical fiber element (2) and arranged in a second surface of the optical waveguide block, the object end (9).
8. The optical endoscope (1) according to claim 7, wherein the fiber element (2) comprises a multicore fiber, and wherein the two or more optical waveguides (7) are coupled to the fiber element (2) such that at a coupling end (8) the two or more optical waveguides (7) are aligned with a core (10) of the multicore fiber.
9. The optical endoscope (1) according to claim 8, wherein the core (10) of the multicore fiber is a single core at the operating wavelength.
10. The optical endoscope (1) according to claim 7, wherein the fiber element (2) comprises a multimode fiber (16), and wherein the two or more optical waveguides (7) are coupled to the multimode fiber (16) via a photonic lantern portion (17) formed in a rigid material of the optical waveguide block (6).
11. The optical endoscope (1) according to any of claims 7 to 10, wherein the object end (9) is a flat surface inclined or perpendicular with respect to the longitudinal axis of the optical fiber element (2).
12. The optical endoscope (1) according to claim 11, wherein the two or more optical waveguides (7) are fanned out from the coupling end (8) to the object end (9) such that the inter-core spacing at the object end (9) is larger than the inter-core spacing at the coupling end (8).
13. The optical endoscope (1) according to any one of claims 7 to 10, wherein the object end (9) is curved, in particular hemispherical.
14. The optical endoscope (1) according to claim 13, wherein the mapping of the spatial distribution of the ends of the two or more optical waveguides (7) at the coupling end (8) to the ends of the two or more optical waveguides (7) at the object end (9) is mirror symmetric with respect to a plane (13) extending parallel to the longitudinal axis of the optical fiber element (2).
15. The optical endoscope (1) of any one of the preceding claims, wherein further optics (15), in particular one or more GRIN lenses and/or one or more microlenses, are coupled with the optical waveguide block (6).
16. The optical endoscope (1) according to any of the preceding claims, wherein the optical waveguide block (6) is at least partially covered by an electrically conductive layer (24), in particular wherein the electrically conductive layer (24) is transparent or translucent at an operating wavelength of the optical endoscope (1).
17. The optical endoscope (1) according to any of the preceding claims, wherein the optical waveguide block (6) comprises or consists of one or more planar chips (26, 27).
18. A method of manufacturing an optical endoscope, comprising the steps of:
providing a fiber optic element having a proximal end and a distal end,
an optical waveguide block comprising a rigid material is provided,
forming two or more optical waveguides in the rigid material, an
The optical waveguide block is connected to the distal end of the optical fiber element.
Technical Field
The present invention relates to an optical endoscope comprising a fiber optic element having a proximal end and a distal end.
Background
Optical endoscopes are instruments used to view the interior of a volume through a small opening. Endoscopes are commonly used in medicine to view the interior of the human body. However, the use of endoscopes is not limited to medicine. Endoscopes are also used for visual inspection of workpieces such as engines, turbines, and the like. Endoscopes used for such technical purposes are sometimes referred to as "borescopes". The term "endoscope" as used herein shall refer to both medical and non-medical uses.
Endoscopes typically comprise flexible optics that direct light between a so-called "distal end" inside the object to be examined and a so-called "proximal end" outside the object. Typically, but not always, there are some miniaturized scanning and/or imaging devices at the distal end and more complex optics at the proximal end, the purpose of which includes magnifying the transmitted image onto a digital image sensor or eyepiece. Endoscopes most commonly obtain scattered images, but fluorescence imaging and optical coherence tomography are also widely used.
For flexible optics, optical fibers are commonly used. Among the possible fiber types, fiber bundles as well as multimode fibers may be used. Multi-core optical fibers have also been commonly used.
One important limitation associated with the use of optical fibers is the low numerical aperture of the optical fiber, which results in a smaller acceptance angle and thus a smaller field of view.
One method known from WO 2017/016663 a1 uses an endoscope with a flexible tubular sheath containing optical fibers. A distal tip having a plurality of three-dimensionally distributed optical ports is described, including a flexible waveguide. These waveguides extend through the same number of optical fibers into the body of the endoscope or are coupled to a multiplexer that connects to several or one optical fiber up to the proximal end of the endoscope.
The technique for producing an endoscope with a corresponding distal tip is cumbersome and expensive. Moreover, the flexible waveguides connecting the optical ports to the proximal end or multiplexer have a high probability of breaking during manufacture or during use of the latter, if appropriate packaging is not used (since they must undergo strong bending). In addition, significant signal loss occurs when a cascade of multiplexers including couplers and splitters is used. For many applications, this additional optical loss is detrimental, if not totally hindering the function of the device. This solution is also difficult to adapt to different fiber geometries, e.g. to different multicore fiber geometries.
It is therefore an object of the present invention to provide an improved optical endoscope which is mechanically more reliable and adaptable in use.
This object is achieved by an optical endoscope according to
Disclosure of Invention
According to the invention, an optical waveguide block is arranged at the distal end of the optical fiber element, wherein the optical waveguide block comprises a rigid material in which two or more optical waveguides are formed. Since two or more optical waveguides are formed in a rigid material, the invention allows long-term stability and higher mechanical reliability compared to known solutions using flexible waveguides.
As described above, the use of the optical endoscope is not particularly limited. The endoscope may be an endoscope for medical purposes or for non-medical purposes. At the proximal end, imaging optics and/or an image sensor and/or an eyepiece may be provided. The imaging optics may include elements for magnifying the transmitted image onto a digital image sensor or an eyepiece.
The fiber optic element may be flexible. However, the fiber optic element may also be rigid.
In particular in the common flexible sheath, the optical fiber element may particularly comprise one or more optical fibers. The common flexible casing may be made of plastic, in particular an elastomer.
The optical waveguide block may be a block-shaped or solid member (not hollow). In other words, the optical waveguide block may not include a cavity in which the optical waveguide is disposed. Alternatively, two or more optical waveguides may be embedded in the rigid material of the optical waveguide block, respectively.
The optical waveguide block may be rigidly coupled to the distal end of the optical fiber element. Thus, the optical waveguide block may be fixed or immovable relative to the distal end of the optical fiber element. The optical waveguide block may be coupled or fixed to the distal end of the optical fiber element by mechanical, adhesive (chemical) and/or melt (thermal) fixation.
An optical waveguide block may be coupled to the distal end of the fiber optic element such that light may be transmitted to the proximal end of the endoscope via the two or more optical waveguides and the fiber optic element. For example, a butt coupling may be implemented.
There is no particular limitation on the number of optical waveguides in the optical waveguide block. The actual number depends on the desired application. For many applications, four or more optical waveguides may be used.
Two or more optical waveguides may be arbitrarily arranged within the optical waveguide block depending on the desired application. The optical waveguides may in particular be arranged in a three-dimensional (3-D) non-intersecting manner. The optical waveguide may also extend in two dimensions (2-D). One or more of the optical waveguides may be curved. One or more of the optical waveguides may be straight or unbent. If both ends of all waveguides are arranged on the same plane, the optical waveguides are considered to be arranged in a 2D distribution, otherwise in a 3D distribution.
The two or more optical waveguides may be single mode or multi-mode waveguides. By increasing the cross-section and/or refractive index contrast of the waveguide, it is possible to switch from a single mode waveguide to a multi-mode waveguide. The refractive index contrast corresponds to the refractive index difference between the waveguide and its surrounding medium (cladding).
The two or more optical waveguides may be integrally formed with the rigid material of the optical waveguide block. In other words, the two or more optical waveguides may be formed of the rigid material itself. In this way, no separate elements need to be introduced into the optical waveguide block, which results in a simplified structure with high mechanical reliability.
The two or more optical waveguides may in particular be formed by portions of a rigid material having a higher refractive index than surrounding portions. Thus, the optical waveguide can be formed by a positive refractive index change in the rigid material. The surrounding portion of the rigid material may form a cladding of the optical waveguide.
In particular, two or more optical waveguides may be obtained by ultra-fast laser writing through the volume of the optical waveguide block. The ultra-fast laser writing is preferably performed with laser pulses having a duration of less than 1 ps.
Filters or other optical elements, in particular obtained by ultrafast laser writing, may be formed in the optical waveguide block. For example, one or more FBG (Fiber Bragg Grating) filters may be formed in an optical waveguide block, in particular in one or more optical waveguides.
The rigid material is optically transparent at the operating wavelength of the optical endoscope. It may also be optically transparent to the laser used for ultra-fast laser engraving. The operating wavelength of the optical endoscope may be below 2 μm, in particular below 1.6 μm, for example between 1.3 μm and 1.55 μm.
The optical waveguide block may be composed of a rigid material. The rigid material may particularly comprise or consist of glass, polymer and/or semiconductor. Examples of materials are silicates and/or multicomponent glasses, perfluorinated polymers, silicon and silicon nitride.
Each of the two or more optical waveguides may comprise an end facing the optical fiber element and arranged in a first surface of the optical waveguide block, a so-called coupling end, and an end facing away from the optical fiber element and arranged in a second surface of the optical waveguide block, a so-called object end. When using an endoscope, the object end may particularly face the object. The two or more optical waveguides may in particular form a tube or channel connecting the coupling end and the object end. Thus, geometrically, two or more optical waveguides are similar to optical fibers. As mentioned above, the cladding may be provided by a rigid material surrounding the optical waveguide.
The optical fiber element may comprise a multi-core optical fiber, wherein the two or more optical waveguides are coupled to the optical fiber element such that the two or more optical waveguides are aligned with cores of the multi-core optical fiber at a coupling end. In other words, butt coupling of the cores of the multi-core optical fiber and the optical waveguides in the optical waveguide block can be achieved. The waveguide block may be index matched to the optical fiber element. Thus, the optical loss can be reduced.
Each core of the multi-core optical fiber may be a single core at the operating wavelength. Single mode waveguides are compatible with coherent imaging techniques such as optical coherence tomography.
Additionally or alternatively, the optical fibre element may comprise a multimode optical fibre, wherein the two or more optical waveguides are coupled to the multimode optical fibre via a photonic lantern portion formed in a rigid material of the optical waveguide block. In this way, the multiplexing section (multiplexing section) used in the related art can be omitted.
The photonic lantern corresponds to an optical element that connects a multimode waveguide to a plurality of waveguides having fewer modes, particularly single modes.
The geometry of the optical waveguide block is not particularly limited. The geometry of the optical waveguide within the rigid material is also not particularly limited. Both of which may depend on the desired application.
The optical waveguide block may be rotationally symmetric, for example in the form of a cylinder or a truncated cone. The optical waveguide block may also have the form of two or more rotationally symmetric elements, e.g., a cylinder and a hemisphere, which are joined to each other.
The optical waveguide block may include or consist of one or more planar chips. Each planar chip may include one or more optical waveguides. The waveguide may be curved. Each planar chip may further comprise a multiplexer and/or a demultiplexer formed therein, in particular by ultra-fast laser writing. As used herein, "planar chip" refers to a geometric form whose extension in one direction (thickness) is significantly less (at least less than three times) than the extension in the other two directions (length, width). In its simplest form, a planar chip may be a rectangular plate. More than one planar chip may be connected to each other to form more complex geometries for the optical waveguide block. For example, two planar chips may be arranged orthogonally to each other, in particular such that each planar chip is divided in half by the other of the two planar chips.
The coupling end may be a polished flat surface perpendicular to the longitudinal axis of the optical fiber element.
The object end may be a flat surface that is inclined or perpendicular with respect to the longitudinal axis of the fiber optic element. By using a sloped surface, back reflections can be minimized or eliminated.
The two or more optical waveguides may in particular fan out from the coupling end towards the object end such that the inter-core spacing at the object end is larger than the inter-core spacing at the coupling end. In this case, the field of view of the endoscope can be enlarged without changing the solid angle.
The object end may be flat polished.
The object end may be curved. In particular the end of the object may be hemispherical. In this way, the planar 2-D distribution of the waveguide ends present at the coupling end can be mapped to a 3-D hemisphere. In this way, the solid angle and thus the field of view can be enlarged.
The end of the object may be continuously or discontinuously curved. The object end can also consist of a plurality of flat polished facets which are joined together to form a curved, in particular hemispherical, surface.
The mapping of the spatial distribution of the ends of the two or more optical waveguides at the coupling end to the ends of the two or more optical waveguides at the object end may be mirror symmetric with respect to a plane extending parallel to the longitudinal axis of the optical fiber element. In other words, the optical waveguides in the optical waveguide block may intersect a plane extending parallel to the longitudinal axis when extending from the coupling end to the object end. In this way, a larger radius of curvature for the optical waveguide can be achieved, thereby reducing curvature losses. Optical waveguides extending from both sides of the plane may intersect the plane at different locations, thereby avoiding intersecting waveguides. In this way, the coupling between the waveguides can also be kept at an acceptably low level.
The plane extending parallel to the longitudinal axis may comprise the axis of symmetry of the optical fiber element and may thus correspond to the plane of symmetry of the optical fiber element. The plane may also form a plane of symmetry of the optical waveguide block coupled to the optical fiber element. The plane may also comprise the axis of rotational symmetry of the optical waveguide block if the optical waveguide block is rotationally symmetric. As mentioned above, the plane may also form a symmetry plane for distributing the optical waveguides in the optical waveguide block. Instead of a plane of symmetry, the axis of symmetry of the fiber element or the optical waveguide block may be used as a reference for some embodiments.
Additional optics, in particular one or more GRIN (graded-index) lenses and/or one or more microlenses, may be coupled to the optical waveguide module. For example, additional optical elements may be used to focus the light.
For example, a separate microlens may be coupled to each end of the optical waveguide at the object end of the optical waveguide block.
The one or more microlenses may be made of fused silica, silicon, or any other material that is transparent at the operating wavelength of the endoscope. The one or more microlenses may in particular be plano-convex lenses.
The optical waveguides in the optical waveguide block may be arranged such that waveguides having an end portion at the coupling end with a radial distance smaller than a predetermined distance from the longitudinal axis of the optical fiber element are bent towards the side of the end portion of the object, while waveguides having a radial distance at the coupling end with a radial distance larger than the predetermined distance from the longitudinal axis of the optical fiber element continue to a forward portion of the end portion of the object. This configuration again allows for a reduction in curvature loss due to the omission of a small radius of curvature of the waveguide near the side of the optical waveguide block. The predetermined distance may be more than one quarter and less than three quarters of the radial extension of the optical waveguide block at the coupling end, in particular half the radial extension of the optical waveguide block at the coupling end.
In this case, the longitudinal axis of the optical fiber element is considered to extend into the optical waveguide block to form a reference axis for the optical waveguide block. The longitudinal axis of the optical waveguide block does not necessarily coincide with the longitudinal axis of the optical fiber element. If the optical waveguide block is rotationally symmetric, the axis of rotation of the symmetry may coincide with the longitudinal axis of the optical fiber element. In other words, the axis of symmetry of the optical waveguide block may be aligned with the longitudinal axis of the optical fiber element. In this case, the axis of symmetry of the optical waveguide block may be similarly used as the reference axis.
As used herein, a "side portion" of an object end refers to a surface area of the optical waveguide block that faces in a direction inclined at an angle greater than or equal to 45 ° and less than or equal to 135 ° with respect to a reference axis of the optical waveguide block (e.g., an extension corresponding to a longitudinal axis of the optical fiber element). Accordingly, the "forward portion" of the object side means a surface area of the optical waveguide block facing in a direction inclined at an angle of less than 45 ° with respect to the reference axis of the optical waveguide block, and the "backward portion" means a surface area of the optical waveguide block facing in a direction inclined at an angle of more than 135 ° with respect to the reference axis of the optical waveguide block. For these considerations, the reference axis is considered to have a direction away from the distal end of the fiber optic element. Thus, the "forward portion" of the end of the object faces away from the distal end of the fiber optic element. The respective angle between the surface normal of the respective surface area and the reference axis can be measured. The surface normal may be considered to have a direction facing away from the optical waveguide block.
The optical waveguide block may be at least partially covered by the conductive layer. The conductive layer may be electrically coupled to another conductor extending to the proximal end of the optical endoscope. Via the conductor and the conductive layer of the optical waveguide block, an electrical current can be transmitted to the distal end for ablation (ablation) purposes.
The conductive layer covering the optical waveguide block may be transparent or translucent, especially at the operating wavelength of the optical endoscope. To this end, the conductive layer may be formed of a transparent or translucent material and/or the conductive layer may have a thickness that allows a predetermined fraction of light at the operating wavelength of the optical endoscope to pass through the layer without being scattered. The predetermined fraction may be 50% or more.
Possible materials for the conductive layer include wide bandgap semiconductor materials such as indium tin oxide or aluminum doped zinc oxide, ultra-thin metals, silver nanowires and/or metal grids. For example, ultra-thin metals and metal grids can be combined to achieve high optical transmission at wavelengths above 1 μm while still maintaining low resistance (high conductance). For medical applications, the material of the electrically conductive layer or at least its outer surface needs to be compatible with human tissue. For such applications, gold may be used as the material of the conductive layer or its outer surface. The outer surface refers to a surface of the conductive layer that may come into contact with human tissue when the optical endoscope is used.
Alternatively or additionally, the conductive layer may comprise openings for light to enter the two or more optical waveguides. In other words, the opening may form an optical port for two or more optical waveguides.
If the electrically conductive material covering the optical waveguide block is transparent or translucent at the operating wavelength of the optical endoscope, it is not necessary to provide openings for light to enter the two or more optical waveguides. In other words, in this case, there is no need to form such an opening or port. Thus, manufacturing can be simplified.
The present invention further provides an optical waveguide block for an optical endoscope, the optical waveguide block comprising a rigid material, wherein two or more optical waveguides are formed in the rigid material. The optical waveguide block may include any one or more of the features described above.
The present invention also provides a method of manufacturing an optical endoscope, comprising the steps of:
providing a fiber optic element having a proximal end and a distal end,
an optical waveguide block comprising a rigid material is provided,
forming two or more optical waveguides in the rigid material, an
The optical waveguide block is connected to the distal end of the optical fiber element.
The two or more optical waveguides may in particular be formed by ultra-fast laser writing.
The optical endoscope, and in particular the optical waveguide block, may include any one or more of the features described above.
Advantageous embodiments will now be described in conjunction with the accompanying drawings.
Drawings
Fig. 1 shows a basic arrangement of an optical endoscope according to the invention in a schematic view;
FIG. 2 shows part of an optical endoscope according to a first embodiment of the present invention;
FIG. 3 shows a portion of an optical endoscope according to a second embodiment of the present invention;
FIG. 4 illustrates an exemplary optical waveguide block for an optical endoscope in accordance with the present invention;
FIG. 5 illustrates another exemplary optical waveguide block for an optical endoscope in accordance with the present invention;
FIG. 6 shows part of an optical endoscope according to a third embodiment of the present invention;
FIG. 7 illustrates another exemplary optical waveguide block for an optical endoscope in accordance with the present invention;
FIG. 8 shows part of an optical endoscope according to a fourth embodiment of the present invention;
FIGS. 9a and 9b illustrate a photonic lantern that may be used with an optical endoscope according to the present invention;
FIG. 10 shows part of an optical endoscope according to a fifth embodiment of the present invention;
FIG. 11 shows part of an optical endoscope according to a sixth embodiment of the present invention;
FIG. 12 illustrates another exemplary optical waveguide block for an optical endoscope in accordance with the present invention; and
fig. 13 shows another exemplary optical waveguide block for an optical endoscope according to the present invention.
Detailed Description
Fig. 1 shows in a schematic way the basic setup of an optical endoscope according to the invention. The
At the
The optical fiber element 2 extends in a longitudinal direction defining a longitudinal axis of the
Fig. 2 shows a first embodiment of the invention. The optical fiber element 2 comprises a multicore optical fiber having a plurality of cores 10 coated in a common flexible polymer jacket 11. Many different types of multicore fibers are known. The invention is not particularly limited to any particular embodiment for multi-core optical fibers, nor to any particular arrangement of optical fibers in the fiber element 2.
In this particular embodiment, the
The
Ultrafast laser engraving is known per se and its working principle is as follows: a high intensity focused femtosecond laser beam is applied to a rigid material to induce a permanent positive refractive index change by a multiphoton absorption mechanism. By 3D conversion, the laser focus passes through a block of rigid material, the path traced by the focus thus becoming a light guiding core due to the higher refractive index that it achieves, while the remaining unaltered portion of the block of rigid material provides an effective cladding. Performing multiple scans can write any number of waveguides having any 3-D shape in one piece of rigid material. Various methods may result in the focused laser being shaped other than the desired shape of the waveguide core, such as a slight offset from each other over multiple scans, and annealing of the block of rigid material by heating after ultrafast laser writing.
More details of the use of a femtosecond laser to write a waveguide in glass can be found in k.m. davis, k.miura, N, Sugimoto and k.hirao, "writing a waveguide in glass with a femtosecond laser," optical promo ",
In the
In general, the
In the embodiment of fig. 2, the
In this example, each core 10 of the multi-core fiber of the fiber element 2 is butt-coupled to an end of the
Optionally, at least one additional optical element 12, such as a GRIN rod lens or a micro lens or a plurality of such lenses, may be attached to the
The object end pattern of the
The completely rigid structure of the
Fig. 3 shows another embodiment of the present invention. Compared to the embodiment of fig. 2, the
Fig. 4 and 5 show possible alternatives to the
Fig. 5 further shows an alternative consisting of an
Fig. 6 shows a further embodiment of the invention, which substantially corresponds to the embodiment described with reference to fig. 3. In this case, however, the microlens 15 is fixed at the optical waveguide end at the
Fig. 7 shows an alternative
An optional microlens or GRIN optic is shown as an additional optical element 15 in figure 7.
Fig. 8 shows another embodiment of the invention, which replaces the multicore fibers used for the fiber elements 2 with
Fig. 9a and 9b show a so-called "photon lantern". A photonic lantern is an optical device that connects a multi-mode waveguide to multiple waveguides with fewer modes (possibly only a single mode). Fig. 9a shows an alternative to mapping one
Referring again to FIG. 8, the modes of the multimode
Since endoscopes using multimode optical fibers are sensitive to bending during use, a transfer function must be obtained for efficient operation, as is known per se in the art.
Fig. 10 shows another embodiment of an optical endoscope according to the present invention. For the fiber element 2, a single mode or
If a multimode fibre is used for the fibre optic element 2, the modulus from the larger input waveguide is divided between its branches at each splitting level. Functionally, this alternative is the same as the embodiment described with reference to fig. 8, the only difference being that the
According to an alternative to using a single mode fibre for the fibre optic element 2, each branch acts as a splitter rather than a fan-out device. In this way, single-mode input light propagating towards the
Another embodiment of the present invention is shown with reference to fig. 11. Sometimes, optical endoscopes are intended for radiofrequency ablation of internal tissues. The embodiment of fig. 11 is suitable for this purpose. In particular, around the fiber optic element 2 there is provided a
In alternative embodiments, the
Fig. 12 and 13 show further alternatives for the
In fig. 12, the
In fig. 13, the
In the described embodiment, the optical waveguide formed in the rigid material of the
Although the previously discussed embodiments and examples of the invention have been described separately, it will be appreciated that some or all of the above features may also be combined in different ways. For example, the described optical waveguide block may be used in conjunction with different kinds of optical fiber elements.
In the drawings, several features are shown in a schematic manner only. For example, the optical waveguide block is often shown spaced from the distal end of the optical fiber element. This is for illustration purposes only. The optical waveguide block is in fact coupled with the distal end of the optical fiber element so that light can be transmitted to the proximal end of the endoscope via the two or more optical waveguides and the optical fiber element. For example, a butt coupling may be implemented.
The discussed embodiments are not intended as limitations but rather serve as examples to illustrate features and advantages of the invention. In particular, the pattern of the optical waveguides in the optical waveguide block depends on the desired application. Similarly, while glass is used for the optical waveguide block according to embodiments, the optical waveguide block may be composed of any transparent, rigid material having an appropriate refractive index that can accommodate a 3-D optical waveguide as described above. With the described embodiments, the field of view or solid angle can be increased compared to known optical endoscopes. Which can simultaneously provide a mechanically reliable, inexpensive solution that can be used with any type of optical fiber.
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