Waveguide and method of identifying a waveguide that is too severely curved

Abstract

A waveguide, in particular an optical fiber, is coated and is of flexible configuration so that the waveguide can be laid in an adaptable manner, wherein the coating includes a light-frequency-converting substance so that in the event of UV light or IR light being coupled into the waveguide and an overbent waveguide, visible light escapes from the waveguide at a bend point.

Claims

1. A waveguide, comprising: a coating, wherein the waveguide is of flexible configuration so that the waveguide can be laid in an adaptable manner, and wherein the coating comprises a light-frequency-converting substance, so that in the event of UV light or IR light being coupled into the waveguide and an overbent waveguide, visible light escapes from the waveguide at a bend point.

2. The waveguide according to claim 1, wherein the light-frequency-converting substance has a concentration of less than 5.0 wt. % and more than 0.1 wt. %, based on a total mass of the coating.

3. The waveguide according to claim 1, wherein the light-frequency-converting substance is selected such that the light-frequency-converting substance generates a low-frequency light from a higher-frequency light.

4. The waveguide according to claim 1, wherein the light-frequency-converting substance is selected from the group consisting of a coumarin dye, a cyanine dye, a flavine dye, a luciferin dye, a phycobilin dye, a rhodamine dye, a safranin dye, and a combination of two or more of the aforementioned dyes.

5. The waveguide according to claim 1, wherein the light-frequency-converting substance is selected such that the light-frequency-converting substance generates a higher-frequency light from a low-frequency light.

6. The waveguide according to claim 5, wherein the light-frequency-converting substance is urea.

7. The waveguide according to claim 1, wherein the waveguide further comprises a cladding.

8. The waveguide according to claim 7, wherein the cladding is transparent.

9. A method of identifying a waveguide that is too severely curved, the method comprising: laying the waveguide, coupling in a UV light and/or an IR light, and visually inspecting the waveguide for escaping visible light so that if an escape of visible light is identified, the waveguide is too severely curved, wherein the waveguide comprises a coating, and wherein the coating comprises a light-frequency-converting substance.

10. The waveguide according to claim 1, wherein the waveguide is an optical fiber.

11. The method according to claim 9, wherein the waveguide is an optical fiber.

12. The waveguide according to claim 3, wherein the light-frequency-converting substance is a fluorescent dye.

13. The waveguide according to claim 3, wherein the light-frequency-converting substance is at least one selected from the group consisting of a coumarin dye, a cyanine dye, a flavine dye, a luciferin dye, a phycobilin dye, a rhodamine dye, and a safranin dye.

14. The waveguide according to claim 7, wherein the cladding comprises at least one material selected from the group consisting of a polyimide, an acrylic, and a silicone.

15. The method according to claim 9, wherein the light-frequency-converting substance has a concentration of less than 5.0 wt. % and more than 0.1 wt. %, based on a total mass of the coating.

16. The method according to claim 9, wherein the light-frequency-converting substance is selected such that the light-frequency-converting substance generates a low-frequency light from a higher-frequency light or a higher-frequency light from a low-frequency light.

17. The method according to claim 16, wherein the light-frequency-converting substance generates a low-frequency light from a higher-frequency light, and wherein the light-frequency-converting substance is at least one selected from the group consisting of a coumarin dye, a cyanine dye, a flavine dye, a luciferin dye, a phycobilin dye, a rhodamine dye, and a safranin dye.

18. The method according to claim 16, wherein light-frequency-converting substance generates a higher-frequency light from a low-frequency light, and wherein the light-frequency-converting substance is urea.

19. The method according to claim 9, wherein the waveguide further comprises further comprises a cladding.

20. The method according to claim 19, wherein the cladding is transparent.

Description

[0027] The invention will be explained in more detail below with reference to exemplary embodiments. The single FIGURE shows the following:

[0028] FIG. 1: a schematic diagram of a curved glass fiber, in which visible light is escaping at a bend point

[0029] A glass fiber 101 has a fiber core 103, a coating 105 and a transparent fiber cladding 109 composed of silicone. The fiber core 103 is composed of glass. In a first alternative, the coating 105 comprises 0.4 wt. % rhodamine 6G. Prior to the production process, to this end, the rhodamine 6G was accordingly added in a liquid state to the subsequent coating agent and mixed therewith. The concentration value relates to the coating in the liquid state. The coating agent with the dissolved rhodamine 6G was sprayed on to the fiber core 103 and cured using UV light. Covering with the fiber cladding 109 then took place. Thus, rhodamine 6G particles 107 are arranged in the coating 105.

[0030] In the present case the glass fiber 101 is curved according to a bend radius 131. In addition, a light source 121, which is an LED and which transmits UV light 123, is arranged at a fiber input 106. The UV light 123 emitted by the light source 121 is coupled into the fiber core 103 and is guided on the basis of total internal reflection at the interface between fiber core 103 and coating 105 by means of total internal reflection towards the fiber output 104.

[0031] Since the bend is too severe at a bend point 143 of the glass fiber 101, total internal reflection no longer exists. Thus, the irradiated UV light 123 interacts reciprocally with the rhodamine 6G particles 107 at the bend point 143 in the coating 105, so that visible emergent light 141 is emitted.

[0032] In an alternative, urea is used instead of rhodamine 6G. The concentration of the urea is 2.4 wt. %. Furthermore, in this case infrared light 123 with a wavelength of 1050 nm is coupled into the glass fiber 101 as the light source 121.

[0033] Now, visible light with a wavelength of 525 nm likewise escapes at the bend point 143, wherein the up-conversion of the photons is achieved by urea particles 107.