TY - JOUR
T1 - Optimized laser-written ZBLAN fiber Bragg gratings with high reflectivity and low loss
AU - Bharathan, Gayathri
AU - Fernandez, Toney Teddy
AU - Ams, Martin
AU - Woodward, Robert I.
AU - Hudson, Darren D.
AU - Fuerbach, Alex
PY - 2019/1/15
Y1 - 2019/1/15
N2 - We report the direct femtosecond laser inscription of type-I fiber Bragg gratings (FBGs) into the core of soft-glass ZBLAN fibers. We investigate and compare various fabrication methods such as single pass (line by line), double pass, and stacking (plane by plane) to create the highest reflectivity FBGs (99.98%) for mid-infrared (mid-IR) applications. In addition, we experimentally demonstrate how the parameters that influence the coupling coefficient, i.e., refractive index modulation and overlap factor, can be controlled in these gratings to specifically tailor the FBG properties. The performance of the direct-written type-I gratings after 6 h of annealing is further analyzed, and the reflectivity increases by approximately 10 dB. To the best of our knowledge, this is the first demonstration of temperature-stable mid-IR FBGs with highest coupling coefficient (464 m−1) and lowest loss (<0.5 dB∕cm) without the use of an expensive phase mask.
AB - We report the direct femtosecond laser inscription of type-I fiber Bragg gratings (FBGs) into the core of soft-glass ZBLAN fibers. We investigate and compare various fabrication methods such as single pass (line by line), double pass, and stacking (plane by plane) to create the highest reflectivity FBGs (99.98%) for mid-infrared (mid-IR) applications. In addition, we experimentally demonstrate how the parameters that influence the coupling coefficient, i.e., refractive index modulation and overlap factor, can be controlled in these gratings to specifically tailor the FBG properties. The performance of the direct-written type-I gratings after 6 h of annealing is further analyzed, and the reflectivity increases by approximately 10 dB. To the best of our knowledge, this is the first demonstration of temperature-stable mid-IR FBGs with highest coupling coefficient (464 m−1) and lowest loss (<0.5 dB∕cm) without the use of an expensive phase mask.
UR - http://www.scopus.com/inward/record.url?scp=85059978856&partnerID=8YFLogxK
U2 - 10.1364/OL.44.000423
DO - 10.1364/OL.44.000423
M3 - Article
C2 - 30644916
AN - SCOPUS:85059978856
VL - 44
SP - 423
EP - 426
JO - Optics Letters
JF - Optics Letters
SN - 0146-9592
IS - 2
ER -