Passively Q-switched erbium-doped fiber laser using evanescent field interaction with gold-nanosphere based saturable absorber

Abstract

We demonstrate an all-fiber passively Q-switched erbium-doped fiber laser (EDFL) using a gold-nanosphere (GNS) based saturable absorber (SA) with evanescent field interaction. Using the interaction of evanescent field for fabricating SAs, long nonlinear interaction length of evanescent wave and GNSs can be achieved. The GNSs are synthesized from mixing solution of chloroauricacid (HAuCl4) and sodium citrate by the heating effects of the microfiber's evanescent field radiation. The proposed passively Q-switched EDFL could give output pulses at 1562 nm with pulse width of 1.78 μs, a repetition rate of 58.1 kHz, a pulse energy of 133 nJ and a output power of 7.7 mW when pumped by a 980 nm laser diode of 237 mW.

Passively Q-switched fibre laser based on interaction of evanescent field in optical microfibre with graphene-oxide saturable absorber

“…[12] and comparable to the results of Ref. [23]. On the other hand, the pulse width for the same power region decreases from 3.67 down to 2.28 µs, as shown in Fig.…”

Gold nanorod as saturable absorber for Q-switched Yb-doped fiber laser

“…On the other hand, nonlinear saturable absorption effect widely exists in metallic nanoparticles, which originates from ground state plasmon bleaching [26,27]. Gold nanorods (GNRs), as a type of metallic nanoparticles, are of great interest to be investigated because of their shape-dependent optical properties and potentially wide range of applications in chemical analysis, biological assays, optical imaging and sensing [28].…”

Gold Nanorods as Single and Combined Saturable Absorbers for a High-Energy <named-content content-type="math" xlink:type="simple"> <inline-formula> <tex-math notation="TeX">$Q$</tex-math></inline-formula></named-content>-Switched Nd:YAG Solid-State Laser

“…In the above situation using GNRs as a SA, the achievable maximum pulse energy was 19 J, which was higher than the results obtained both from the GNRs-based Q-switched Er fiber lasers [8], [9] and some emerging SAs Q-switched 1 m solid-state lasers (such as carbon nanotubes, graphene, topological insulator, and MoS 2 [16]- [19]). However, the generated pulses from such a GNRs-based passively Q-switched laser were in the microsecond region, which is attributed to the small effective modulation depth of GNRs-based SA.…”

“…Recently, GNRs have been successfully exploited as SAs for the generation of short pulses in Q-switched or modelocked fiber lasers [6]- [11]. As for the Q-switched Er fiber lasers, pulses at 1562 nm with a pulse width of 1.78 s and a pulse energy of 0.13 J were obtained with the microfiber-based evanescent field interaction scheme [8], while 4.8 s and 0.31 J pulses at 1560 nm were generated in the GNRs film sandwich configuration [9]. Regarding mode-locking operation, 887 fs pulses at 1552 nm and $440 ps pulses at 1039 nm were obtained from GNRs-based modelocked Er and Yb fiber lasers, respectively [10], [11].…”