We propose and demonstrate a new method for fabricating a compact all-fiber spectrometer by using a tilted superstructure fiber grating to couple light out of a fiber core and produce an interference pattern in the near field. The Fourier transform of the interference pattern serves as a direct measurement of the optical input spectrum, and the superstructure grating design offers several degrees of freedom that permit control over the resolution and bandwidth of the spectrometer. For single-wavelength operation, the proposed scheme offers the possibility of making wavelength measurements with picometer-level precision over a broad 80-nm wavelength range while simultaneously providing coarser precision over a 160-nm range.
© 2004 Optical Society of America
(050.2770) Diffraction and gratings : Gratings
(060.2340) Fiber optics and optical communications : Fiber optics components
(120.6200) Instrumentation, measurement, and metrology : Spectrometers and spectroscopic instrumentation
S. Wielandy and S. C. Dunn, "Tilted superstructure fiber grating used as a Fourier-transform spectrometer," Opt. Lett. 29, 1614-1616 (2004)