Mie scattering-based structural unit for optical fiber attenuator and application thereof

Abstract

The invention discloses a Mie scattering-based structural unit for an optical fiber attenuator. The principle is that: an optical fiber is locally modified by a laser direct writing technology, namely a heterogeneous material structure is generated in a modified area. The structure can generate Mie scattering on incident light to realize optical attenuation function, the attenuation capacity of the optical attenuator is effectively adjusted by controlling the refractive index and density of the modified area, the dimension along the radial direction of the optical fiber, and the length of the modified area, and one or more Mie scattering-based structural units for the optical fiber attenuator are in cascade connection to form an adjustable optical fiber attenuator. The optical fiber attenuator prepared by the method can realize uniform optical attenuation in a wide band, has a wide attenuation adjustable range, has no back or weak back reflection, and cannot damage the whole wave guide characteristics when the optical fiber attenuator is used for a photonic crystal optical fiber having a waveguide structure. The optical fiber attenuator is simple in structure, low in cost, high-temperature resistant, high in reliability, low in access loss, small in volume and easy to integrate.

Description

A Structural Unit of Fiber Attenuator Based on Mie Scattering and Its Application technical field The invention belongs to the field of optoelectronic device preparation, in particular to a structural unit of an optical fiber attenuator based on Mie scattering and its application. Background technique When the energy transmitted in the optical path exceeds a predetermined value, it needs to be attenuated, and an optical attenuator is needed at this time. In optical communication and optical sensing, the traditional optical attenuation principles mainly include the following: 1. Control the alignment accuracy of the coupling of two optical fibers to generate coupling errors, and use this error to achieve optical attenuation; 2. Utilize the bending loss of optical fibers, That is to destroy the total reflection condition in the waveguide to achieve light attenuation; 3. Add absorbers or reflective elements in the optical path to perform light attenuation; 4. Periodically cha...

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Problems solved by technology

Tunable optical attenuators based on the above principles usually need to use more complex thermal control or electrical control mechanical devices in order to control physical quantities such as alignment accuracy during fiber coupling, fiber curvature, refractive index change, and effective length of the absorber. In order to realize the control of the attenuation intensity, it is often accompanied by the disadvantages of large insertion loss, slow response speed, overly sensitive to wavelength, and poor mechanical stability

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