FREQUENCY-SELECTIVE NANOSTRUCTURED PLASMONIC ABSORBER BY HIGHLY LOSSY INTERFACE MODE

We report on an existence of a highly lossy interface mode (HLIM) in a designed plasmonic nanostructure for perfect absorption of the incident optical waves. Interactions between the single thin-metallic-layer (TML) and slits arrays for excitation of the HLIM in the proposed plasmonic absorber are investigated, and eigenfrequency formula for the HLIM is derived. Analytical and numerical results show that the HLIM is frequency-selective, opens a narrow and steep absorption band in photonic stopband of the slits arrays. Due to the HLIM lossy characteristic, surface plasmon polaritons are significantly trapped at the TML interface with absorption close to 100%

A new scheme for novel all-optical wavelength conversion with ultrabroad conversion tunability and modulation-transparency

A scheme named “spoof” four wave mixing (SFWM) is proposed, where a dynamic refractive index grating induced by the beating of the co-propagating pump and signal is able to modulate a Bragg grating (BG) to create additional reflective peaks (ARPs) at either side of the unperturbed BG bandgap. When a probe wave located at the wavelength of ARPs is counter-propagating, it is reflected from the induced ARPS while tracking the signal data information but at the new wavelength. In contrast to the well-known FWM, where the induced dynamic refractive index grating modulates photons to create a wave at a new frequency, the SFWM is different in that the dynamic refractive index grating is generated in a nonlinear BG to excite ARPS at either side of the original BG bandgap in reflection spectrum. This fundamental difference enable the SFWM to avoid the intrinsic shortcoming of stringent phase matching required in the conventional FWM, and allows novel all-optical wavelength conversion with modulation format transparency and ultrabroad conversion range, which represents a major advantage for next generation of all-optical networks

Coherent emission of light using stacked gratings

The possibility of temporally and spatially coherent thermal emission has been demonstrated utilizing stacked gratings. We demonstrate that the metallic grating with narrow air slit behaves like a homogeneous slab with large permittivity and small permeability and find that the interaction between the metallic grating and the Bragg grating gives rise to impendence matching at wavelengths located in the photonic band gap of the Bragg grating, which enables the stacked gratings to perform high emission with ultranarrow spectrum and antenna-like spatial response. This paves the way towards the design of a novel infrared source platform for applications such as thermal analysis, imaging, security, biosensing, and medical diagnoses

Blue light generated by intra-cavity frequency doubling of an edge-emitting diode laser with a periodically poled LiNbO₃ crystal

We demonstrate for the first time to our knowledge intra-cavity frequency doubling (ICFD) of an edge-emitter diode laser using a 10 mm-long 5.0 µm periodically poled LiNbO3 (PPLN) crystal. An optical output power of 33 mW second harmonic blue light at 490.5 nm is generated at 1.0 A injection current, equivalent to an overall wall-plug efficiency of 1.8%. The measured M2 values of blue beam are 1.7 and 2.4 along the fast and slow axis