Search

New light sources with low spatial coherence and high brightness are crucial for high‐quality imaging. In this paper, such a light source is reported, which is formed by combining random lasing used as seed light with a multimode fiber (MMF) mediated master oscillator power amplifier (MOPA) for power scaling and spatial decoherence. Experimental results show that the proposed multimode random fiber laser (MM‐RFL), with low noise, high spectral density, and high power efficiency, can achieve a maximum output power of 100.6 W and speckle contrast of as low as 0.037. Furthermore, MM‐RFL‐based speckle‐free imaging is demonstrated. The imaging quality can be improved by increasing the output power of the MM‐RFL as its spatial coherence decreases with an increasing number of effective modes excited in the MMF. Such a MM‐RFL provides a powerful light source for speckle‐free imaging applications where high power and low spatial coherence are essential for high‐quality imaging. [ABSTRACT FROM AUTHOR]

We present a dual longitudinal mode narrow linewidth, injection-seeded, Q-switched fiber ring laser. Deeply modulated pulses near 1.55 μm with a modulation frequency that can be tuned continuously from DC to a demonstrated 25 GHz have been achieved. High peak powers are attained through the use of a reduced-stimulated Brillouin scattering single-clad erbium doped fiber. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 202–204, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23040 [ABSTRACT FROM AUTHOR]

Two‐dimensional hybrid organic–inorganic perovskites have recently attracted attention in various optoelectronic applications. A novel thin film of 2D perovskite (C6H5C2H4NH3)2PbI4 crystallites is synthesized and its nonlinear optical properties are experimentally investigated within the optical gain of an Erbium‐doped fiber. Utilizing its unique nonlinear optical response, efficient mode‐locking of an all‐fiber Erbium laser is demonstrated at the anomalous dispersion regime in both the C‐ and L‐bands stably generating femtosecond pulse trains, where the thin film of 2D perovskite crystallites function as an in‐line saturable absorber. At this anomalous dispersion regime, self‐started femtosecond pulses are generated whose center wavelength are tuned from 1565.9 nm in C‐band and 1604 nm in L‐band by adjusting the optical gain. Furthermore, by managing the chromatic dispersion of the total fiber laser cavity to reach the normal dispersion regime, a stable dissipative soliton is successfully generated in the C‐band with the spectral bandwidth of 15 nm and pulse duration of 3.2 ps. Detailed material properties of the thin film of 2D perovskite crystallites, their characterization, and fiber laser mode‐locking performance is reported. A two‐dimensional crystallites perovskite ((C6H5C2H4NH3)2PbI4) is combined with a fiber laser to confirm its nonlinear optic functionality by generating an ultrafast laser in both transform‐limited soliton and dissipative soliton formats in the entire C‐ and L‐bands. It shows the shortest pulse width, the highest repetition rate, the most stable pulse generation, and the highest slope efficiency compared with 3D perovskite‐based pulse lasers. [ABSTRACT FROM AUTHOR]