A long-period grating formed in a single-mode optical fiber or waveguide can cause light coupling between the guided mode and the co-propagating cladding modes at specific resonance wavelengths and, therefore, produce a transmission spectrum that consists of a series of rejection-bands centered at those wavelengths.
This thesis concerns the fabrication, characterization, and application of fibre Bragg gratings (FBGs). Being in-fibre wavelength-selective reflectors, FBGs have wide applications in optical communication and sensing systems. Compared with conventional bulk-optic gratings, FBGs offer the advantages of low loss, polarisation independence, compatibility
Pointing, acquisition, and tracking (PAT) systems have been widely applied in many applications, from short-range (e.g. human motion tracking) to long-haul (e.g. missile guidance) systems. This dissertation extends the PAT system into new territory: free space optical (FSO) communication system alignment, the