4 results about "Saturation intensity" patented technology

The invention provides a multi-longitudinal-mode fiber laser weak current detection method based on a magnetic rotation sensitive material, and the method comprises the following steps: building a multi-longitudinal-mode fiber laser weak current detection system; a relationship between the magnetic field intensity and the current in the DC coil; determining the relationship between the intra-cavity loss and the Faraday rotation angle of the multi-longitudinal-mode fiber laser resonant cavity within the magnetic field range which does not reach the magnetic saturation intensity of the magneto-optical material; calculating a current value when the magnetic field reaches the magnetic saturation intensity value of the magneto-optical material; when the to-be-measured current value on the coil is between 0 and the critical current, calculating the to-be-measured current value; the magneto-optical sensor is arranged in the multi-longitudinal-mode fiber laser resonant cavity, and the corresponding relation between light intensity change and weak current is constructed through the matching relation between the magneto-optical sensor and the multi-longitudinal-mode fiber laser resonant cavity, so that small current change which is difficult to measure by a traditional sensor can be detected, and high-sensitivity measurement is realized.

This application belongs to the field of saturable absorber technology, and particularly relates to a saturable absorber based on tantalum arsenide quantum dots, its preparation method, and a mode-locked fiber laser. The saturable absorber provided by this application includes a tapered optical fiber and tantalum arsenide quantum dots loaded thereon. The tantalum arsenide quantum dots have excellent nonlinear optical properties and saturation intensity, so when the laser passes through the tantalum arsenide quantum dots on the saturable absorber, the laser reaches saturation quickly, enabling the output of ultrafast laser with a repetition frequency and stable laser mode-locked signal, thereby solving the technical problem of low performance of saturable absorbers based on two-dimensional materials in the prior art.

This application belongs to the field of saturable absorbers, and particularly relates to a saturable absorber based on tantalum nitride quantum dots, its preparation method, and a mode-locked fiber laser. The tantalum nitride quantum dots in the saturable absorber provided by this application, as topological half-metals, exhibit excellent optical properties and saturation intensity. When a laser beam passes through the tantalum nitride quantum dots on the saturable absorber, the laser can quickly reach saturation, enabling the output of ultrafast lasers with a repetition frequency and stable laser mode-locking signal. This solves the technical problem of low performance in existing saturable absorbers based on two-dimensional materials.

The present invention relates to the technical field of fiber lasers, specifically to a preparation method of a spatio-temporal mode-locked fiber laser based on a saturable absorber. In the preparation process, an InP quantum dot saturable absorber is used as the absorber, and the specific steps are as follows: preparation of InP quantum dots; preparation of an InP quantum dot saturable absorber. The present invention uses a saturable absorber of InP quantum dots with a large modulation depth and a low saturation intensity to prepare a spatio-temporal mode-locked fiber laser, which can synchronously lock multiple transverse and longitudinal modes to generate picosecond mode-locked pulses. By selecting a multimode gain fiber, it has a larger mode area, which can reduce the nonlinear effect to meet the growing demand for high-power lasers. Its additional spatial degree of freedom can improve the transmission capacity in optical communication.