In-fiber spectrometer using tilted fiber gratings

Low Thermal Sensitivity Grating Devices Based on Ex-45$^{\circ}$ Tilting Structure Capable of Forward-Propagating Cladding Modes Coupling

“…This functionality has been utilized for several types of device. The most attractive TFBG device is the in-fiber WDM spectrum analyzer [4][5][6], which is a low-cost alternative to lab-based bulky and expensive optical spectrum analyzers and can be potentially incorporated into real application systems.…”

“…Erdogan and Sipe were the first to give a detailed treatment to tilted fiber Bragg grating (TFBG) structures in 1996 [3]. Since then, a handful of application devices utilizing TFBGs were reported, including infiber spectrometer [4][5][6], WDM channel monitoring [7], gain flattening of EDFAs [8] and optical sensor interrogation [9][10][11]. Due to their exceptional polarization sensitivity, TFBGs have also been implemented as in-line polarimeter [12,13], polarization dependent loss equalizer [14,15] and, recently, high-extinction-ratio polarizers [16].…”

Experimental and theoretical characterization of optical signal out-coupling through V-grooved optical fiber cladding

“…In addition, tilted FBGs ͑TF-BGs͒ are good for sensing the power of the core mode because they can couple the core mode to the cladding mode and/or radiation mode. By directly coupling the core mode to the radiation mode, fiber in-line types of spectrometers [1][2][3] and monitors 4 have been developed, which have a coupling efficiency of mostly 0.1ϳ 3%. Because of the low efficiency, they are not suitable for highsensitivity optical receivers.…”

Ultrawide Bandwidth Wavelength Monitor Based on a Pair of Tilted Fiber Bragg Gratings

“…Recently, in-line fiber spectrometers based on tilted fiber Bragg gratings (TFBGs) [7]- [10] have been reported. TFBGs have the ability to diffract light out of the fiber core in a dispersive way.…”

“…The scattered light from several wavelength channels is simultaneously detected on single successive detectors [7] or may be focused onto an array of photodiodes [8], [9]. Wavelength selectivities of 7 nm [7] and 0.1 nm [8] have been reported, respectively. To achieve a higher wavelength selectivity, devices with more than one TFBG have been proposed.…”