Counting Modes in Optical Fibres with Leaky Modes
نویسندگان
چکیده
The number of guided modes in optical fibres is an important aspect of their design and characterisation. Some optical fibres, such as microstructured fibres and Bragg fibres, have no strictly bound modes in the same sense as in conventional step and graded index fibres. All modes in these fibres are leaky so what exactly becomes regarded as a mode becomes important.. We propose a method for counting the number of modes in fibres that takes into account the leaky nature of some modes. The method is based on the loss of each mode and the length of the fibre. This leads to a definition of singlemodedness for fibres with no bound modes.
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