Bandpass filter with adjustable bandwidth based on a press-induced long-period twisted holey-fiber grating.
A bandpass filter with adjustable bandwidth based on a press-induced long-period grating in a twisted holey fiber is presented. By twisting the holey fiber prior to the application of periodic pressure, each rejection band of the nontwisted induced long-period grating is split into two shifted rejection bands that move further apart as the twist ratio increases. This feature results in a wide bandpass filter with controllable bandwidth. A bandpass filter at 1523 nm with adjustable bandwidth from 15 to 65 nm with near-linear response and insertion loss lower than 0.7 dB is demonstrated. Additionally, the bandpass filter can be tuned over 100 nm.
Centro de Investigaciones en Optica A.C., León, Mexico. itorres@cio.mx
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I
Torres-Gómez
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A
Martínez-Ríos
D E
DE
Ceballos-Herrera
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E
Mejía-Beltrán
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R
Selvas-Aguilar