posted on 2024-07-09, 17:00authored byS. P. Yam, Z. Brodzeli, B. P. Kouskousis, C. M. Rollinson, Scott WadeScott Wade, G. W. Baxter, S. F. Collins
A fiber Bragg grating at twice the Bragg wavelength was fabricated by a standard phase mask technique and its two peaks/dips are attributed to the interleaved refractive index modulations along the fiber core that produced a pi-phase-shifted grating.