1.
Opt Lett
; 47(12): 3127-3130, 2022 Jun 15.
Article
En
| MEDLINE
| ID: mdl-35709067
We propose an ultrahigh-order fiber Bragg grating (UHO-FBG) containing dense resonants and its application as a novel filtering device in multi-wavelength lasers. The UHO-FBG is fabricated by femtosecond laser plane-by-plane direct inscription. Thanks to the plane-by-plane inscription, high-order Bragg resonances can be formed with multiple reflectance peaks of comparable reflectance in the range of the fiber operating bandwidth and without the transmission depression of long-period gratings in the transmission spectrum. We also experimentally demonstrate the use of UHO-FBG pairs in a distributed Bragg reflector laser, enabling the excitation of multi-wavelength lasers.