分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: We report the fabrication and optical characterization of Yb3+-doped waveguide amplifiers (YDWA) on the thin film lithium niobate fabricated by photolithography assisted chemo-mechanical etching. The fabricated Yb3+-doped lithium niobate waveguides demonstrates low propagation loss of 0.13 dB/cm at 1030 nm and 0.1 dB/cm at 1060 nm. The internal net gain of 5 dB at 1030 nm and 8 dB at 1060 nm are measured on a 4.0 cm long waveguide pumped by 976nm laser diodes, indicating the gain per unit length of 1.25 dB/cm at 1030 nm and 2 dB/cm at 1060 nm, respectively. The integrated Yb3+-doped lithium niobate waveguide amplifiers will benefit the development of a powerful gain platform and are expected to contribute to the high-density integration of thin film lithium niobate based photonic chip.
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: 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: We demonstrate an on-chip Yb3+-doped lithium niobate (LN) microdisk laser. The intrinsic quality factors of the fabricated Yb3+-doped LN microdisk resonator are measured up to 3.79x10^5 at 976 nm wavelength and 1.1x10^6 at 1514 nm wavelength. The multi-mode laser emissions are obtained in a band from 1020 nm to 1070 nm pumped by 984 nm laser and with the low threshold of 103 {\mu}W, resulting in a slope efficiency of 0.53% at room temperature. Furthermore, the second-harmonic frequency of pump light and the sum-frequency of the pump light and laser emissions are both generated in the on-chip Yb3+-doped LN microdisk benefited from the strong \c{hi}(2) nonlinearity of LN. These microdisk lasers are expected to contribute to the high-density integration of LNOI-based photonic chip.
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.
分类: 光学 >> 量子光学 提交时间: 2023-02-19
摘要: We overcome the difficulty in realizing a monolithic waveguide-coupled microring laser integrated on erbium-doped thin film lithium niobate (Er: TFLN) using photolithography assisted chemo-mechanical etching (PLACE) technique. We demonstrate an integrated single-frequency microring laser operating around 1531 nm wavelength. The PLACE technique, enabling integrated Er: TFLN photonics with low propagation loss, can thus be used to realize low cost mass production of monolithic on-chip microlasers with applications ranging from optical communication and photonic integrated circuit (PIC) to precision metrology and large-scale sensing.
分类: 材料科学 >> 材料科学(综合) 提交时间: 2022-10-06
摘要: A novel hybrid laser additive manufacturing process based on laser shock modulation of molten pool was proposed in this work. The flow behavior residual stress, and microstructure of the molten pool were comprehensively characterized by a combination of experiments and simulations. The relationship between the convection behavior, evolution of microstructure, and enhancement of residual stress induced by laser shock modulation was established. Laser shock modulation assisted additive manufacturing process exhibits high efficiency in residual stress control. The hidden mechanism in microstructure evolution and residual stress enhancement was expected to be related to intensified molten pool convection, uniform solute distribution and improved cooling rate induced by shock wave. The hybrid additive manufacturing process strategy based on laser shock modulation provides a new approach for heat and mass modulation in hybrid manufacturing.