Optica

Mid-spatial-frequency (MSF) surface figure errors can significantly degrade high-resolution imaging performance. This study proposes a design-stage workflow for MSF-error evaluation and tolerance allocation.

In the defect detection of spherical optical surfaces, illumination is critical for high-quality dark-field scattering imaging. In dark-field scattering imaging of spherical elements, it is hard to achieve correspondence between aperture angles and curvature radii, and continuously adjustable aperture angles are impractical for engineering applications. To solve these issues, a multi-level aperture angle matching scheme for annular light sources is proposed in this paper.

Spherical targets are extensively employed in high-precision 3D vision measurement for system calibration and industrial positioning due to their omnidirectional rotational invariance. However, under the perspective projection model, the oblique intersection between the camera tangent cone and the image plane forms a projected conic contour, which appears as a quasi-elliptical contour in practical imaging.

This study presents a novel multilayer metal–dielectric (MD) thin-film bandpass filter, to our knowledge, designed to overcome the low rejection-band ratio of conventional all-dielectric filters. By integrating a silver (Ag) layer within a dielectric stack and employing aluminum oxide $(\text{Al}_{2}\text{O}_{3})$ as both a phase-matching and protective layer, the filter achieves an enhanced rejection-band ratio of 3.1:1 while improving adhesion and preventing metal oxidation.

Multi-band composite detection is a core technology for achieving high-precision detection of targets at all times and under all weather conditions. To address the laser backscattering issue in the coaxial laser transmit-receive design of conventional multiband optical systems, this paper proposes a four-channel common-aperture composite detection optical system integrating laser emission, laser reception, long-wave infrared detection, and visible-light detection.

Single-component multicolor luminescence is vital for advanced optical materials, yet its mechanism remains challenging to rationalize due to multiple environmentally regulated excited-state processes. In this Letter, the multicolor emission mechanism of PBT was elucidated using photophysical measurements and quantum chemical calculations.

Despite the urgent need for high-sensitivity, fast-response, ambient-temperature CO2 sensing in environmental, industrial, and biomedical applications, conventional optical platforms suffer from weak light–matter interactions and poor signal contrast. Here, we propose and demonstrate a highly sensitive CO2 gas sensor based on a metafiber platform integrated with a functional polymer thin film.

In space-based gravitational wave detection, ultra-stable oscillators are employed as the primary frequency reference; however, the detection sensitivity is fundamentally constrained by the inherent clock jitter of these oscillators. To mitigate such jitter-induced noise, a clock transfer link, consisting of a frequency distribution module and an electro-optic modulator, is required to be established.

Mo3+-activated halide perovskites can exhibit narrowband spin-flip luminescence through downconversion and upconversion. However, because Mo3+ absorbs weakly in the near-infrared (NIR) region, NIR excitation generally produces only weak room-temperature Mo3+ downconversion emission and Mo3+ upconversion emission only at low temperatures. Here, we demonstrate that Yb3+ effectively sensitizes Mo3+ in Cs2NaInCl6 double perovskites.

A numerical study is presented on the interaction of the Kerr nonlinearity and stimulated Brillouin scattering (SBS) in high-energy, high-peak-power, and narrow-linewidth pulsed Yb-doped fiber amplifiers. Numerical simulations demonstrate that for high-power nanosecond pulses, a strong Kerr-induced nonlinear phase shift generates a frequency sweep that exceeds the Brillouin gain bandwidth, thereby diminishing the SBS gain.