Polarization-dependent loss and birefringence in long-period fiber gratings

Bachim, Brent L.; Gaylord, Thomas K.

doi:10.1364/ao.42.006816

Cited by 88 publications

(44 citation statements)

References 33 publications

(43 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…4(a), the PDL of the PBF without LPFG is 0.6±0.5dB and is increased to as high as 25dB around the resonant wavelength after an LPFG was written. This is much larger than that of the CO 2 -laser-induced LPFGs in conventional SMFs (~1.2dB) [24]. The large PDL is believed to be due to the significant asymmetry in waveguide cross-section [ Fig.…”

Section: Characterization Of Lpfgsmentioning

confidence: 96%

Long period gratings in air-core photonic bandgap fibers

Wang¹,

Jin²,

Ju³

et al. 2008

Opt. Express

122

102

View full text Add to dashboard Cite

Long period fiber gratings in hollow-core air-silica photonic bandgap fibers were produced by use of high frequency, short duration, CO 2 laser pulses to periodically modify the size, shape and distribution of air holes in the microstructured cladding. The resonant wavelength of these gratings is highly sensitivity to strain but insensitive to temperature, bend and external refractive index. These gratings can be used as stable spectral filters and novel sensors.

show abstract

Section: Characterization Of Lpfgsmentioning

confidence: 96%

Long period gratings in air-core photonic bandgap fibers

Wang¹,

Jin²,

Ju³

et al. 2008

Opt. Express

122

102

View full text Add to dashboard Cite

show abstract

“…This increase in the cladding mode birefringence also contributes to the enhancement of the PDL in the LPFG written with side laser irradiation [19]. Besides, in Fig.…”

Section: Discussionmentioning

confidence: 81%

“…This difference may counteract the effect of PDL in the resonant dip change. Meanwhile, the resonant bandwidth and the light power coupled into the fiber from a certain polarization state may also affect the relationship between PDL and the wavelength separation, as mentioned in [19].…”

Section: Discussionmentioning

confidence: 99%

Long-period fiber gratings fabricated by use of defocused CO_2 laser beam for polarization-dependent loss enhancement

Yang

Wang

2009

J. Opt. Soc. Am. B

View full text Add to dashboard Cite

An alternative of the long-period fiber grating (LPFG) fabrication method has been developed in this work by use of defocused CO 2 laser pulse scanning, which is achieved by moving the laser beam focus plane slightly away from the fiber cladding surface. By increasing the distance shift from the cladding surface, the area with refractive index change also increases on the side with laser irradiation, which leads to an apparent mode field profile distortion at the resonant wavelength of the LPFG. Such a distortion in the mode field profile significantly increases the polarization-dependent loss of the LPFG. Moreover, for the cascaded LPFGs fabricated by use of this technique, the maximum polarization-dependent loss obtained can be largely increased from 7 to 17.8 dB, with a maximum dip in the wavelength change of 0.45 nm.

show abstract

“…The maximum PDL of 1.35 dB in the CO 2 -laser-carved LPFG is close to the value, i.e., 1.2 dB, of that in the CO 2 -laser-induced LPFGs without periodic grooves. 9,10 This indicates that the periodic grooves will not enhance the polarization dependence in the LPFG. The reason is that, although periodic grooves increase the refractive index modulation, they are confined within the outer cladding region and do not strongly influence the asymmetry of index profile within the cross section of the core and inner cladding of the LPFG.…”

mentioning

confidence: 96%

“…3,[9][10][11] Consequently, a clear polarization dependence exists in the CO 2 -laser-carved LPFG as shown in Fig. 7, where the average loss and the polarization dependent loss ͑PDL͒ are measured by an Agilent 81910A photonic all-parameter analyzer.…”

mentioning

confidence: 99%

Asymmetric long period fiber gratings fabricated by use of CO2 laser to carve periodic grooves on the optical fiber

Wang

Jin

et al. 2006

Applied Physics Letters

104

View full text Add to dashboard Cite

An asymmetric long period fiber grating ͑LPFG͒ with a large attenuation of −47.39 dB and a low insertion loss of 0.34 dB is fabricated by use of focused CO 2 laser beam to carve periodic grooves on one side of the optical fiber. Such periodic grooves and the stretch-induced periodic microbends can effectively enhance the refractive index modulation and increase the average strain sensitivity of the resonant wavelength of the LPFG to −102.89 nm/ m . The resonant wavelength and the peak attenuation of the LPFG can be tuned by ϳ12 nm and ϳ20 dB, respectively, by the application of a stretching force. © 2006 American Institute of Physics. ͓DOI: 10.1063/1.2360253͔ Long period fiber grating ͑LPFG͒ is one of the widely used passive optical fiber devices. Various LPFG fabrication techniques have been demonstrated, including ultraviolet laser irradiation, 1 CO 2 laser heat, 2,3 hydrofluoric acid etching corrugation, 4 and application of periodic microbend. 5 The strain sensitivity obtained for the CO 2 -laser-induced LPFGs without physical deformation is usually very low, only −0.45 nm/ m . 2,3 In this letter, a technique of fabricating asymmetric LPFG by use of focused CO 2 laser beam to carve periodic grooves on one side of the optical fiber is presented. The LPFGs obtained exhibit a large peak transmission attenuation of −47.39 dB and a low insertion loss of 0.34 dB. Moreover, the average strain sensitivity of resonant wavelength of the LPFG is increased to −102.89 nm/ m .Our experimental setup is shown in Fig. 1. A CO 2 laser ͑SYNRAD 48-1͒ with a maximum output power of 10 W, a light-emitting diode light source, and an optical spectrum analyzer ͑HP 70004A͒ were used. The optical fiber ͑Corning SMF-28͒ was situated in the focal plane of the CO 2 laser beam. One of the fiber ends was fixed and a small weight of ϳ5 g was used at the free end of the fiber to avoid the weight-induced macrobend and to provide a tensile strain in the fiber. The focused CO 2 laser beam scanned repeatedly for M times along the X direction at a location, corresponding to the first grating period, of the fiber via a two-dimensional optical scanner under the computer control. Then the laser beam was shifted by a grating period along the Y direction and scanned repeatedly for M times to generate the next grating period. This scanning and shifting process was carried out for N times ͑N is the number of grating periods͒ until the final grating period was created. The above mentioned process was repeated for K cycles until a high quality LPFG was produced. The repeated scanning of the focused CO 2 laser beam created a local high temperature in the fiber, which led to the gasification of SiO 2 on the surface of the fiber. As a result, periodic grooves were carved on the fiber as shown in Fig. 2. Such grooves induce periodic refractive index modulation along the fiber axis due to the photoelastic effect, thus creating a LPFG. The typical depth and width of the grooves obtained in our LPFGs were ϳ15 and ϳ50 m, respectively. The depth of the grooves dep...

show abstract

Polarization-dependent loss and birefringence in long-period fiber gratings

Cited by 88 publications

References 33 publications

Long period gratings in air-core photonic bandgap fibers

Long period gratings in air-core photonic bandgap fibers

Long-period fiber gratings fabricated by use of defocused CO_2 laser beam for polarization-dependent loss enhancement

Asymmetric long period fiber gratings fabricated by use of CO2 laser to carve periodic grooves on the optical fiber

Contact Info

Product

Resources

About