title: Generation of synchronized picosecond pulses by a 1.06-µm gain-switched laser diode for stimulated Raman scattering microscopy.
abstract: We propose that a gain-switched laser diode (GS-LD) can be used as a picosecond laser source for stimulated Raman scattering (SRS) microscopy. We employed a 1.06-µm GS-LD to generate ~13-ps pulses at a repetition rate of 38 MHz and amplified them to >100 mW with Yb-doped fiber amplifiers. The GS-LD was driven by 200-ps electrical pulses, which were triggered through a toggle flip-flop (T-FF) so that the GS-LD pulses were synchronized to Ti:sapphire laser (TSL) pulses at a repetition rate of 76 MHz. We found the timing jitter of GS-LD pulses to be approximately 2.7 ps in a jitter bandwidth of 7 MHz. We also show that the delay of electrical pulses can be less sensitive to the optical power of TSL pulses by controlling the threshold voltage of the T-FF. We demonstrate the SRS imaging of polymer beads and of HeLa cells with GS-LD pulses and TSL pulses, proving that GS-LD is readily applicable to SRS microscopy as a compact and stable pulse source.
authors.forename: Kyoya
authors.initials: K
authors.lastname: Tokunaga
authors.forename: Yi-Cheng
authors.initials: YC
authors.lastname: Fang
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yokoyama
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Ozeki