Short-wave infrared (SWIR) spectrometer has been a critical device in spectral analysis fields like agriculture, [1,2] environmental monitoring, [3] astronomy, [4,5] etc. Conventionally, the infrared spectrometer is bulky and delicate due to the spectral division device, such as grating and prism, which limited its applications. The demand and potential for compact spectrometers are enormous for portable and on-chip applications like smartphone spectrometer, [6,7] hyperspectral imaging, [8][9][10] etc. The key to miniaturizing spectrometers is replacing the bulky spectral split devices with miniature photonic devices. [11] Besides, combing with reconstruction algorithms such as compressed sensing and machine learning, the incident light spectrum can be reconstructed with a few numbers of filters. [8,[12][13][14] In recent years, such reconstructive micospectrometer based on Si-based complementary metal-oxide-semiconductor (CMOS) sensors in visible range are primarily investigated. In comparison, the microspectrometer in SWIR range is much more useful to acquire object information in practical applications. Strategies based on photonic devices slab, [9,10,[15][16][17][18][19] quantum dot (QD) slab, [20][21][22] nanowire, [23,24] have been proposed for portable and on-chip microspectrometer. The number and variety of filter spectra determined the resolution of reconstructive microspectrometer. Micro-nano photonic device filters like photonic crystal (PC), metamaterial, Fabry-Perot (FP) cavities can acquire distinctive spectra by varying structure morphology parameters. Material-based filters like QD slab can acquire different spectra by adjusting their size, composition, or bias. Those filters mentioned above are usually fabricated onto a separated slab and then pasted or bonded with a detector chip. In practical applications, the separated slab is fragile and difficult to well-matching with detector pixels, leading to spectral crosstalk and other problems. Recently proposed detector-only reconstructive microspectrometer based on nanowires, [23,24] black phosphorus [25] is ultra-compact without external filters. It has a stable structure with wavelength scale size, but the number of response spectra is hard to increase significantly and limits its resolution.Among these micro-nano filters, FP microcavities array has low spectral correlation coefficient by varying its cavity length, Short-wave infrared (SWIR) information is critical for material analysis, imaging sensing, and other fields. To acquire SWIR spectrum with compact devices, strategies for reconstructive microspectrometer have emerged, such as photonic crystal and quantum dot filter. However, the current SWIR microspectrometer needs many filters with insufficient resolution. In this work, the authors develop a SWIR chip-spectrometer based on Fabry-Perot microcavities array which can be fabricated by using fast and low-cost UV laser directwriting grayscale lithography. The ultra-compact chip-spectrometer can work in a very wide range from 900 to 1700 nm wi...

Mid-infrared (MIR) semiconductor laser sources are essential for applications in gas detection, infrared imaging, and high-speed free space optical communications. At present, the dynamic wavelength tunability of MIR lasers based on lead salt, antimonide, and quantum cascade lasers is limited and their compact size as well as heterogeneous integration are still challenging. Two-dimensional (2D) materials, used as optical gain materials, have the flexible tunability and compatible van der Waals integrations-providing many new possibilities for constructing MIR laser sources of large tunability and high integration. Here, wide-wavelength tunable MIR vertical cavity surface emitting lasers (VCSELs) integrated on silicon substrates are realized based on 2D black arsenic phosphorus (b-As x P 1−x ). The emission wavelength of the optically pumped laser device is demonstrated to be tuned from 3.42 to 4.65 μm at room temperature, which could be controlled by adjusting the alloy composition and thickness of the gain media b-As x P 1−x . The tunable MIR VCSEL device would pave the way for further exploration of 2D materials-based IR lasers working as on-chip light sources.

Metasurface attracts much attention but lacks the modulation ability along the beam propagation direction, which confines its ability to control the wavelength and polarization of light. We propose a new concept of metainterface by embedding a two-dimensional metamaterial in a layered structure with vertical control ability. It can hugely improve the light control power and generate excellent characteristics while keeping simple fabrication processes. A high-performance spectro-polarimetric filter, which is based on the interface composed of one-dimensional photonic crystals and 10 nm thick Al grating, is fabricated for demonstration. Experimental results show that it can simultaneously have a polarization extinction ratio (PER) of 800 and a spectral resolution power (SRP, λ/Δλ) of 113, which are, respectively, 74 and 9 times better than the recently obtained best results of the metasurface. Moreover, it can break the limitation of diffraction and achieve much higher PER with limited size gratings. Because of these characteristics, it has great potential in miniature and integrated spectropolarimeters.