0.3 mJ‐Per‐Pulse 280–2530 nm Compact White Laser and Its Single‐Shot Spectroscopy Application

ABSTRACT Supercontinuum white lasers have received extensive attention as they offer new opportunities in various basic science and technology applications. It is a long pursuit to achieve balanced performance in three critical factors: bandwidth, pulse energy, and spectral flatness. In this work, we use an intense 1.0 mJ per pulse 1500 nm near‐infrared (NIR) femtosecond laser to pump a nonlinear optical module composed of a cascaded bare lithium niobate (LN) crystal offering good third‐order nonlinearity (third‐NL) induced spectral broadening and a chirped periodic‐poled lithium niobate (CPPLN) crystal offering excellent second‐order nonlinearity (second‐NL) in terms of high‐efficiency broadband second‐ and third‐harmonic generation. By engineering the synergy of second‐NL and third‐NL, we achieve an intense compact white laser with ultrabroad and flat spectrum (280–2530 nm @ 25 dB, covering deep‐ultraviolet (DUV), visible (Vis), NIR, and mid‐infrared (MIR)), pulse energy (0.3 mJ), and high repetition (1 kHz). The developed DUV‐Vis‐NIR‐MIR ultrashort pulse white laser allows us to probe and measure the absorption spectra for various samples, including sodium copper chlorophyllin, carbon dots, ethanol, and water, only through a single shot of white laser pulse, opening new avenues in the cross‐field of ultrafast and ultrabroadband laser spectroscopy and high‐speed spectrography by using a compact‐sized pump laser.