## 3 Experimental Characteristics of Multicolored Pulses  
### Experimental Setups  
Various experimental setups for multicolored laser pulse generation have been reported in the literature. The main differences between these setups are the methods for preparing the two pump laser beams. [PERSON] and his coworkers used two femtosecond pulses from a dye-laser amplifier system, with Beam 1 (561 nm, 40 fs) and Beam 2 (618 nm, 80 fs), and a pulse energy of 20 \(\upmu\)J for each beam [54]. Figure 2: Calculated output parameters of generated sidebands. Dependence of **(a)** central wavelength of Beam 1 for minimum phase-mismatching; **(b)** the wavelength; and **(c)** the exit angles of generated sidebands on the order number at different crossing angles; **(d)** Dependence of exit angle of the generated sidebands on the center wavelength at three different cross-angles, 1.40\({}^{\circ}\), 1.87\({}^{\circ}\), and 2.57\({}^{\circ}\), in different nonlinear media; **(e)** Phase mismatching of the sidebands from AS1 to AS4 at 1.87\({}^{\circ}\) and 2.34\({}^{\circ}\) in 1 mm fused silica [60]. [PERSON] used two OPA systems, pumped with a commercial Ti:sapphire amplifier [61]. The SHG signals of the signal and idler pulses from the two OPAs were used as the pump pulses for the generation of multicolored sidebands. The central wavelength and pulse energy of the two pump beams were 630 nm/1-3 \(\upmu\)J and 584 nm/1-3 \(\upmu\)J. There were also some other differences, including the Ti:sapphire amplifier pulse, and the supercontinuum generated in bulk materials [58]. We have used two experimental setups for multicolored pulse generation. As shown in Figure 3, we used Type-1 experimental setup for most of our work. The pump source was a 1 kHz Ti:sapphire regenerative amplifier laser system (35 fs/2.5 mJ/1 kHz/800 nm, Micra + Legend-USP, Coherent, Santa Clara, CA, USA). The pump laser was split into four beams for different uses. One beam (Beam 1), with energy of 300 \(\upmu\)J, was focused into a krypton-gas-filled hollow-core fiber with inner and outer diameters of 250 \(\upmu\)m and 3 mm, and a length of 60 cm. The spectrum of Beam 1 broadened to a range extending from 600 to 950 nm after transmission through the hollow-core fiber, while the pulse energy decreased to about 190 \(\upmu\)J, due to coupling and propagation loss. A pair of chirped mirrors and two glass wedges were applied to compensate for the chirp of Beam 1 with broadband spectrum. A nearly transform-limited pulse, with a pulse duration of \(\sim\)10 fs, was obtained by changing the bounce times on the chirped mirrors and the insertion of the glass wedges. Negatively and positively chirped pulses also can be obtained for different experiments. Beam 1 was then spectrally filtered with band-pass filters (BPF) short-wavelength-pass filters (SPF), or long-wavelength-pass filters (LPF) in different experiments. A concave mirror with a focal length of 600 cm was used to focus Beam 1 into the nonlinear medium (G1). Beam 2 was focused into the nonlinear medium by a lens with a focal length of 1 m. The fourth beam (Beam 4) was used to characterize the generated multicolored pulses with the cross-correlation frequency-resolved optical gating (XFROG) technique [74] in a 10 \(\upmu\)m-thick BBO crystal. Figure 4 shows the schematic of Type-2 setup, which was used for the generation of low-threshold multicolored sidebands and 2-D multicolored arrays in a diamond plate. Another Ti:sapphire laser system (35 fs/2.5 mJ/1 kHz/800 nm, Spitfire ACE, Spectra-Physics) was used as the  
Figure 3: Type-1 experimental setup. VND: variable neutral-density filter. G1: nonlinear medium for multicolored sidebands generation. G2: nonlinear medium for pulse measurement with an X-FROG system [74]. pump source, and a beam with pulse energy of 150 \(\upmu\)J was used in the experiment. A BK7 glass plate with a thickness of 3 mm was used to spectrally broaden the laser pulse using a self-phase modulation (SPM) process.