A tunable, gain-clamped (GC) double-pass Erbium-doped fiber amplifier (EDFA) with a linear laser-cavity configuration has been demonstrated. It solves the problems existing in the conventional linear-cavity GC-EDFA based on two fiber Bragg gratings (FBGs), in which the clamped-gain is very difficult to be tuned. In the new GC-EDFA, the lasing oscillation for clamping the gain is produced in a l...

Abstract Developing semiconductors with broad gain bandwidth has always been at the forefront of laser technologies. The variation in feedback resonators can provide a useful tool for producing relatively wide range discrete lasing wavelengths. However, wavelength is limited by fundamental semiconductor itself. Gain engineering full‐color though remains daunting challenge. Considering abundant ...

Pulse generation often requires a stabilized cavity and its corresponding mode structure for initial phase-locking. Contrastingly, modeless cavity-free random lasers provide new possibilities for high quantum efficiency lasing that could potentially be widely tunable spectrally and temporally. Pulse generation in random lasers, however, has remained elusive since the discovery of modeless gain ...

The lack of a high-power, relatively low-cost and compact terahertz (THz) source in the range 0.3-3x10 Hz is the major obstacle in progressing on biomedical and material studies at these wavelengths. A high-gain, single pass seeded FEL technique allows to obtain high power THz pulses of a high spectral brightness. We describe an ongoing project at the Neptune laboratory where a ~ 1kW seed pulse...

In this paper, a compact, planar printed microstrip line fed pentagonal shape ultra-wideband antenna with triple band-notched characteristics is proposed and investigated. By incorporating pair of mirrored Γ-shape, L-shape slots in the patch bent C-shape parasitic strip at backside patch, tunable band notched responses are realized. The fabricated on Rogers RO3003 substrate permittivity 3.0 thi...

We design an all-optical tunable delay line based on both dispersive and wavelength conversion stages involving modulational instability of a twofrequency pump field propagating in a highly birefringent fiber. More precisely, we numerically show that, by varying the frequency separation between the two orthogonally polarized pump waves, we achieve a controllable and continuous delay of hundreds...