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Air core fibre coupler for ultrafast lasers and power splitting

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Partner keyword: 
Optical Networks and Systems
Laser Related
Fibre Optics


A Singapore institute of higher learning has developed a novel air core fibre coupler, that can be used in mid-infrared (IR) or ultraviolet (UV) regions where conventional solid fibre couplers cannot cover. An air core fibre component is ideal for building an all-fibre ultrafast mid-IR fibre laser cavity for ultrafast lasers and power splitting applications. The technology provider is interested in licensing or commercial partnerships with technical assistance with MNEs/SMEs of all sizes.



A fibre optic coupler is a fiberised component used as an essential building block in a fibre-based optical system such as a fibre laser, fibre resonator, fibre interferometer or fibre communication network.

However, a conventional fibre coupler is composed of two solid fibres thermally fused side by side. Hence, its performance is limited by a solid core.

The institute has developed a hollow/air core fibre coupler that is based on anti-resonant fibre technology with two air cores in the coupler behaving as an individual anti-resonant fibre core. Anti-resonant features such as broad band transmission and low loss are kept intact with the air core coupler.

An entire transmission window is coupled between the two air cores. The operation spectral range can be customised by adjusting design parameters, as the proprietary fibre structure allows customised designs to be fulfilled via conventional fibre fabrication processes. The coupling ratio is also variable by applying mechanical strain.

The air core fibre coupler offers:
- Air gap-enabled optical power coupling
- Variable coupling strength by mechanical tension
- Air cores that can be customised for desired operation spectral windows
- No optical limitation imposed by material properties
- Design compatible to glass or polymer materials

Potential applications include:
- Mechanically variable fibre coupler or splitter as an alternative to conventional fixed ratio couplers or splitters
- Applications in a mid-IR or UV laser cavity or resonator
- An optical multiplexing device in the emerging air core fibre based network
- Ultrafast laser power splitter/delivery
- Air core fibre-based resonators
- Air core fibre-based interferometers
- Sensors utilising the variable coupling feature
- Sensors utilising the air cores to be filled with functional materials
- A combination of the above

The Singapore institute of higher learning seeks licensing or commercial agreements with technical assistance with MNEs/SMEs of all sizes.

Advantages & innovations

Cooperation plus value: 
The anti-resonant air fibre coupler offers the following advantages and innovations: - Ability to construct an optical system with all-fibre mid-IR ultrafast fibre lasers - Variety of specialty fibres for high power laser applications with fabrication technology for large mode area Yb-doped and Tm-doped fibres available for custom requirements - Step-index fibre, photonic bandgap fibre, air core fibre, multi-core fibre, air core fibre coupler and customised fibres

Stage of development

Cooperation stage dev stage: 
Available for demonstration

Partner sought

Cooperation area: 
The technology provider is interested in the following types of partnerships with MNEs or SMEs of all sizes: i) Licensing agreement - The partner could license the technology for further development and introduce it to its customers. ii) Commercial agreement with technical assistance - The partner could utilise the technology with technical support from the technology provider.

Type and size

Cooperation task: 
SME 11-50,SME <10,>500 MNE,251-500,SME 51-250,>500