分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: We demonstrate an on-chip single-mode Er3+-doped thin film lithium niobate (Er: TFLN) laser which consists of a Fabry-P\'erot (FP) resonator based on Sagnac loop reflectors (SLRs). The fabricated Er: TFLN laser has a footprint of 6.5 mmx1.5 mm with a loaded quality (Q) factor of 1.6x105 and a free spectral range (FSR) of 63 pm. We generate the single-mode laser around 1550-nm wavelength with a maximum output power of 44.7 {\mu}W and a slope efficiency of 0.18 %.
分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: Integrated single-mode microlasers with ultra-narrow linewidths play a game-changing role in a broad spectrum of applications ranging from coherent communication and LIDAR to metrology and sensing. Generation of such light sources in a controllable and cost-effective manner remains an outstanding challenge due to the difficulties in the realization of ultra-high Q active micro-resonators with suppressed mode numbers. Here, we report a microlaser generated in an ultra-high Q Erbium doped lithium niobate (LN) micro-disk. Through the formation of coherently combined polygon modes at both pump and laser wavelengths, the microlaser exhibits single mode operation with an ultra-narrow-linewidth of 98 Hz. In combination with the superior electro-optic and nonlinear optical properties of LN crystal, the mass-producible on-chip single-mode microlaser will provide an essential building block for the photonic integrated circuits demanding high precision frequency control and reconfigurability.
分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: We demonstrate a robust low-loss optical interface by tiling passive (i.e., without doping of active ions) thin film lithium niobate (TFLN) and active (i.e., doped with rare earth ions) TFLN substrates for monolithic integration of passive/active lithium niobate photonics. The tiled substrates composed of both active and passive areas allow to pattern the mask of the integrated active passive photonic device at once using a single continuous photolithography process. The interface loss of tiled substrate is measured as low as 0.26 dB. Thanks to the stability provided by this approach, a four-channel waveguide amplifier is realized in a straightforward manner, which shows a net gain of ~5 dB at 1550-nm wavelength and that of ~8 dB at 1530-nm wavelength for each channel. The robust low-loss optical interface for passive/active photonic integration will facilitate large-scale high performance photonic devices which require on-chip light sources and amplifiers.
分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: Integrated on-chip microdisk lasers have attracted great attention as a light source of compact size, low lasing threshold and narrow bandwidth. However, challenges remain unresolved in terms of single mode operation at high output power while maintaining the ultra-narrow bandwidth. In this work, we demonstrate monolithically integrated on-chip single-frequency microdisk lasers coupled with bus-waveguides fabricated by photolithography assisted chemo-mechanical etching. Owing to the high-Q factor of a polygon whispering gallery mode formed in the microdisk and long cavity lengths (e.g., 409 um and 1 mm), a microdisk laser with a narrow linewidth of 0.11 MHz and a maximum output power of 62.1 uW has been achieved at room temperature.
分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: We demonstrate an electrically driven compact hybrid lithium niobate microring laser by butt coupling a commercial 980-nm pump laser diode chip with a high quality Er3+-doped lithium niobate microring chip. Single mode lasing emission at 1531 nm wavelength from the Er3+-doped lithium niobate microring can be observed with the integrated 980-nm laser pumping. The compact hybrid lithium niobate microring laser occupies the chip size of 3 mmx4mmx0.5 mm. The threshold pumping laser power is 6 mW and the threshold current is 0.5 A (operating voltage 1.64 V) in the atmospheric temperature. The spectrum featuring single mode lasing with small linewidth of 0.05 nm is observed. This work explores a robust hybrid lithium niobate microring laser source which has potential applications in coherent optical communication and precision metrology.