Emerging Low‐Dimensional Materials for Nonlinear Optics and Ultrafast Photonics

Abstract

Low-dimensional (LD) materials demonstrate intriguing optical properties, which lead to applications in diverse fields, such as photonics, biomedicine and energy. Due to modulation of electronic structure by the reduced structural dimensionality, LD versions of metal, semiconductor and topological insulators (TIs) at the same time bear distinct nonlinear optical (NLO) properties as compared with their bulk counterparts. Their interaction with short pulse laser excitation exhibits a strong nonlinear character manifested by NLO absorption, giving rise to optical limiting or saturated absorption associated with excited state absorption and Pauli blocking in different materials. In particular, the saturable absorption of these emerging LD materials including two-dimensional semiconductors as well as colloidal TI nanoparticles has recently been utilized for Q-switching and mode-locking ultra-short pulse generation across the visible, near infrared and middle infrared wavelength regions. Beside the large operation bandwidth, these ultrafast photonics applications are especially benefit from the high recovery rate as well as the facile processibility of these LD materials. The prominent NLO response of these LD materials have also provided new avenues for the development of novel NLO and photonics devices for all-optical control as well as optical circuits beyond ultrafast lasers.

Structural Engineering of Low‐Dimensional Metal–Organic Frameworks: Synthesis, Properties, and Applications

“…[9][10][11][12][13][14][15][16][17][18][19][20] Great efforts have been also devoted to preparing nanoscale MOF crystals with controllable size and morphology, in order to achieve enhanced performance in certain applications. [30][31][32][33][34][35][36][37] Since the discovery of carbon nanotubes (CNTs) in the early 1990s, 1D nanostructures, such as nanowires, nanotubes, and nanorods, have been extensively investigated because of their unique geometrical and electronic characteristics. [25][26][27][28][29] Low-dimensional (LD) nanomaterials are of particular interest due to their anisotropic-tunable properties, which greatly influence their performances.…”

Near‐Infrared Broadband Polymer‐Dot Modulator with High Optical Nonlinearity for Ultrafast Pulsed Lasers

“…Ultrafast lasers are indispensable tools in many areas of science and engineering, including spectroscopy, optical communication, high‐precision processing, biomedical imaging, and laser therapy . In principle, the generation of ultrafast pulses is based on passive Q‐switching or mode‐locking techniques, in which saturable absorbers are used as nonlinear optical (NLO) modulators.…”

2D GeP as a Novel Broadband Nonlinear Optical Material for Ultrafast Photonics

“…Nonlinear optical (NLO) materials, as basic elements of photonic devices (such as lasers, all‐optical modulators, switches, and thresholds), have attracted wide attention since the first laser beam appeared . 2D materials possess many attractive photonic properties, including wide‐ranging linear optical absorption, Pauli‐blocking‐induced saturated absorption, strong light–matter interaction, ultrafast relaxation time, and high optical nonlinearity, which endow them with great potential as NLO materials .…”

“…Nonlinear optical (NLO) materials, as basic elements of photonic devices (such as lasers, all-optical modulators, switches, and thresholds), have attracted wide attention since the first laser beam appeared. [1][2][3][4] 2D materials possess many attractive photonic properties, including wide-ranging linear optical to mid-infrared region and an ultrashort recovery time property of several tens of femtoseconds. [21] Unfortunately, BP is unstable in air and degrades easily to phosphoric acid under the action of light, oxygen, and water, [22] which limits the long-term use of photonic devices based on BP.…”