Directional control of thermal emission over its broad wavelength range is a fundamental challenge. Gradient epsilon‐near‐zero (ENZ) material supporting Berreman mode has been proposed as a promising approach. However, the bandwidth is still inherently limited due to the availability of ENZ materials covering a broad bandwidth and additional undesired omnidirectional modes in multilayer stacking with increased thickness. Here, we show that broadband directional thermal emission can be realized beyond the previously considered epsilon‐near‐zero and Berreman mode region. We then establish a universal approach based on effective medium theory to realizing ultra‐broadband directional thermal emitter. We numerically demonstrate strong (emissivity >0.8) directional (80 ± 5°) thermal emission covering the entire thermal emission wavelength range (5–30 μm) by using only two materials. This approach offers a new capability for manipulating thermal emission with potential applications in high‐efficiency information encryption, energy collection and utilization, thermal camouflaging, and infrared detection.

Pulsed lasers alter the optical properties of semiconductors and affect the photoelectric function of the photodetectors significantly, resulting in transient changes known as bleaching. Bleaching has a profound impact on the control and interference of photodetector applications. Experiments using pump–probe techniques have made significant contributions to understanding ultrafast carrier dynamics. However, there are few theoretical studies to the best of our knowledge. Here, carrier dynamic models for semiconductors and photodetectors are established, respectively, employing the rectified carrier drift-diffusion model. The pulsed laser bleaching effect on seven types of semiconductors and photodetectors from visible to long-wave infrared is demonstrated. Additionally, a continuous bleaching method is provided, and the finite-difference time-domain (FDTD) method is used to solve carrier dynamic theory models. Laser parameters for continuous bleaching of semiconductors and photodetectors are calculated. The proposed bleaching model and achieved laser parameters for continuous bleaching are essential for several applications using semiconductor devices, such as infrared detection, biological imaging, and sensing.

Capturing transient events on ultrafast time scales demands imaging at up to trillions of frames per second (Tfps). Yet leading methods, including compressed sensing-based photography, time-resolved shadowgraphy, and other active approaches, are limited by bulky optics, high cost, and repeated measurements. Here, we propose angular spectrum-encoded single-shot ultrafast photography (ASUP). ASUP combines the time-wavelength mapping of a chirped-pulse probe with dispersion-encoded angular spectrum information. The latter is realized by a multilayer dielectric thin-film photonic chip, inversely designed using a deep Q-network (DQN) reinforcement-learning framework. This chip performs pixel-level encoding without the need for bulky dispersive optics. An enhanced residual convolutional neural network with Transformer blocks then decodes the measurements to reconstruct high-fidelity ultrafast dynamics. In experiments, ASUP achieves 0.83 Tfps with six frames in a single exposure and captures picosecond laser-induced damage and plasma dynamics in metal films. ASUP delivers performance comparable to state-of-the-art ultrafast photography while remaining compact, highly integrated, and cost-effective. It overcomes key limitations of existing ultrafast imaging and offers a scalable solution for high-speed optical diagnostics, laser-matter interactions, and transient phenomena studies.