Abstract
We report the first demonstration of two-stage optical fiber pulse compression using a grating-pair technique1 and pulse narrowing effect of high-order soliton propagation.2 The former technique requires a fiber with positive group-velocity dispersion, while the latter requires a fiber with negative dispersion. We used two different dispersion-shifted fibers3 to satisfy both requirements for one carrier wavelength (1.319 μm). We have achieved a combined compression factor of 1100, which is the largest reported to date. Figure 1 is a schematic of the experimental setup and beam paths with symbolic pulse shapes superimposed to illustrate the relative pulse durations at various places. The light source is a 1.319-μm mode-locked Nd:YAG laser, which outputs 100-ps (FWHM) pulses at 100-MHz repetition rate. The first stage consists of fiber F1, parallel grating pair G1 and G2, and mirror M1 which reflects the light and makes it pass the grating pair twice. Successively, M2 and L2 couple the light into fiber F2, which alone stands for the second stage. Fiber F1 has a 2-km length and 18.5-ps/nm · km dispersion (zero dispersion at 1.59 μm), Gratings are separated by 2.4 m and have 1180 grooves/mm. Fiber F2 has a 40-m length and ~3.75-ps/nm · km dispersion (zero dispersion at 1.275 μm). We obtained 50× compression (i.e., 2-ps pulses, see Fig. 2) from the first stage compression. It is clearly shown that the use of dispersion-shifted fiber eliminates the pulse pedestal. We have also incorporated the polarization-maintaining property4 into dispersion-shifted fiber for the first stage. This has eliminated the slow drift in the output power caused by polarization-dependent transmission of the grating pair. We obtained 22× compression from the soliton compression, i.e., 2 ps is reduced further to 90 fs (see Fig. 3). The 22× compression factor agrees with the theory5 for an N = 7 soliton, where N is the soliton order. We are investigating the possibility of eliminating the pedestal for soliton compression using the nonlinear birefringence effect.2 In conclusion, we have used the polarization-maintaining dispersion-shifted fibers to produce 90-fs pulses (= 20 optical periods) from a commercially available laser. These pulses at 1.319 μm are useful for lightwave technology.
© 1986 Optical Society of America
PDF ArticleMore Like This
K. Tai and A. Tomita
WN2 OSA Annual Meeting (FIO) 1985
K. Tai, A. Tomita, A. Hasegawa, and J. L. Jewell
THC2 Conference on Lasers and Electro-Optics (CLEO:S&I) 1986
B. Zysset and H. P. Weber
WK10 Conference on Lasers and Electro-Optics (CLEO:S&I) 1986