Conference Agenda

Recent advances in optical fiber sensing systems based on wavelength-swept lasers (WSLs) are presented. An ultra-wideband WSL with a scanning bandwidth exceeding 440 nm enables one-to-one mapping between spectral and temporal domains, allowing real-time interrogation without complex signal processing. This approach is applied to strain sensing using cholesteric liquid crystal elastomers and to volatile organic compound detection using porous cholesteric liquid crystal films integrated on fiber ferrules. The results demonstrate high sensitivity, fast response, and stable operation, indicating the suitability of WSL-based systems for practical real-time optical sensing applications.

Spatial light modulators (SLM) require reliable wavelength calibration for accurate operation in photonic applications. Here, we present a single-shot hyperspectral method for the phase calibration of a 10-bit liquid-crystal-on-silicon (LCOS) SLM over the visible spectrum. The use of a hyperspectral camera enables dense spectral sampling while preserving the spatial information of a calibration pattern containing multiple phase levels. Combined with broadband illumination from a supercontinuum laser and measurements with crossed/parallel polarizers, this approach retrieves the retardance as a function of wavelength and addressed gray level and enables direct generation of wavelength-specific phase lookup tables.

We present a lookup-table-based correction for timing errors in SPAD arrays used for non-line-of-sight (NLOS) imaging. On-chip TDC manufacturing tolerances cause three types of pixel-dependent errors: gain error (~6% pixel-to-pixel mean bin-width variation), relative offset error, and differential non-linearity (~0.6% bin-to-bin width fluctuations). These degrade NLOS reconstruction quality when transients from multiple pixels are combined. Our correction relies on two calibration measurements: a continuous-illumination acquisition providing relative bin widths, and a multi-peak acquisition anchoring the absolute time scale. Multiplying relative widths by the absolute mean yields the true width of every bin, from which a backward-resampling LUT is built that maps measured histograms onto a uniform temporal grid. Our method is deterministic and executes in ~4 µs per frame, enabling real-time operation. Validated on experimental data from a 32×32 SPAD camera with phasor-field reconstruction and on simulated confocal data, the correction yields visibly sharper reconstructions, higher SSIM, and improved contrast transfer across all spatial-frequency bands.

A high resolution graphdiyne-based surface plasmon resonance sensor is proposed for miRNA detection. The proposed sensor consists of multiple layer structure of BK7-prism/Au/Ta₂O₅/graphene/GDY. The Fresnel multilayer transfer-matrix formalism is employed to optimize the structure of sensor. The theoretical simulation is performed to calculation the resolution of the proposed sensor in the range refractive index of 1.3316-1.3416.

Superluminescent diodes (SLDs) are compact, efficient light sources with low coherence, suitable for applications such as solid-state lighting, micro-projectors and displays. Blue-emitting SLDs are especially relevant due to their broadband emission at short wavelengths. They are based on laser diodes where optical feedback is suppressed to favor amplified spontaneous emission. Conventional methods require complex designs and fabrication steps. Here, we propose an alternative approach using controlled scattering defects introduced by pulsed laser ablation in a commercial 405 nm GaN laser diode. This disrupts feedback without modifying the epitaxial structure, achieving 1.8 mW output power and 5.9 nm bandwidth, demonstrating a simple route to broadband sources.