We present an innovative and practical scheme of building a miniaturized wavemeter, with the advantages of low cost, high reliability and simple structure. Through a calibration test by a 780 nm external cavity diode ...We present an innovative and practical scheme of building a miniaturized wavemeter, with the advantages of low cost, high reliability and simple structure. Through a calibration test by a 780 nm external cavity diode laser(ECDL), the results show that our system gets a wavelength resolution of better than 1 pm, measurement accuracy of better than 2 pm(corresponding to a frequency of 1 GHz), and a measurement range of 8.5 nm. Finally, the multi-mode comparison test between our system and a commercial spectrum analyzer further indicates the high-precision, miniaturization and low cost of the proposed system, which shows that it is particularly suitable for ECDL and atom cooling and trapping experiments. The system design, experimental results and conclusions are of definite significance as a fine reference for other ranges of wavelength.展开更多
Speckle patterns generated by the intermodal interference of multimode fibers enable accurate broadband wavelength measurements.However,the measurement speed is limited by the frame rate of the camera that captures th...Speckle patterns generated by the intermodal interference of multimode fibers enable accurate broadband wavelength measurements.However,the measurement speed is limited by the frame rate of the camera that captures the patterns.We propose a compact and cost-effective ultrafast wavemeter based on multimode and multicore fibers,which employs spectral-spatial-temporal mapping.The speckle patterns generated by multimode fibers enable spectral-to-spatial mapping,which is then sampled by a multicore fiber into a pulse sequence to implement spatial-to-temporal mapping.A high-speed single-pixel photodetector is employed to capture the pulse sequence,which is analysed using a multilayer perceptron to estimate the wavelength.The feasibility of the proposed wavelength estimation method is experimentally verified,achieving a measurement rate of 100 MHz with a resolution of 2.7 pm in a 1 nm operation bandwidth.展开更多
A dual system and dual wavelength spectrophotometry (DSDWS) used to simultaneously determine Zr and Hf were proposed. Zr(Hf)-XO-CIMAB and Zr(Hf)-CAB-CDMAA-Triton X-100 were chosen as a pair of chromophoric systems. Th...A dual system and dual wavelength spectrophotometry (DSDWS) used to simultaneously determine Zr and Hf were proposed. Zr(Hf)-XO-CIMAB and Zr(Hf)-CAB-CDMAA-Triton X-100 were chosen as a pair of chromophoric systems. The difference of chromophoric behaviours between Zr and Hf is increased by the addition of hydrogen peroxide as masking agent and by adjustment of acidity. The apparent molar absorptivities of Zr and Hf are 2.0×105 and 5.0×104 L·mol-1·cm-1 respectively. The procedure is simple and rapid.展开更多
Spectroscopy is the basic tool for studying molecular physics and realizing biochemical sensing.However,it is challenging to realize sub-femtometer resolution spectroscopy over broad bandwidth.Broadband and high-resol...Spectroscopy is the basic tool for studying molecular physics and realizing biochemical sensing.However,it is challenging to realize sub-femtometer resolution spectroscopy over broad bandwidth.Broadband and high-resolution spectroscopy with calibrated optical frequency is demonstrated by bridging the fields of speckle pattern and electro-optic frequency comb.A wavemeter based on a whispering-gallery-mode barcode is proposed to link the frequencies of a probe continuous-wave laser and an ultrastable laser.The ultrafine electro-optic comb lines are generated from the probe laser to record spectrum of sample with sub-femtometer resolution.Measurement bandwidth is a thousandfold broader than comb bandwidth,by sequentially tuning the probe laser while its wavelength is determined.This approach fully exploits the advantages of two fields to realize 0.8-fm resolution with a fiber laser and 80-nm bandwidth with an external cavity diode laser.The spectroscopic measurements of an ultrahigh Q-factor cavity and gas molecular absorption are experimentally demonstrated.The compact system,predominantly constituted by few-gigahertz electronics and telecommunication components,shows enormous potential for practical spectroscopic applications.展开更多
基金supported by the National Natural Science Foundation of China(No.51275523)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20134307110009)+1 种基金the Graduate Innovative Research Fund of Hunan Province(No.CX20158015)the Excellent Graduate Innovative Fund of NUDT(No.B150305)
文摘We present an innovative and practical scheme of building a miniaturized wavemeter, with the advantages of low cost, high reliability and simple structure. Through a calibration test by a 780 nm external cavity diode laser(ECDL), the results show that our system gets a wavelength resolution of better than 1 pm, measurement accuracy of better than 2 pm(corresponding to a frequency of 1 GHz), and a measurement range of 8.5 nm. Finally, the multi-mode comparison test between our system and a commercial spectrum analyzer further indicates the high-precision, miniaturization and low cost of the proposed system, which shows that it is particularly suitable for ECDL and atom cooling and trapping experiments. The system design, experimental results and conclusions are of definite significance as a fine reference for other ranges of wavelength.
基金supported by the National Key Research and Development Program of China(2021YFB2800902)National Natural Science Foundation of China(61931010,62225110)Hubei Province Key Research and Development Program(2020BAA006).
文摘Speckle patterns generated by the intermodal interference of multimode fibers enable accurate broadband wavelength measurements.However,the measurement speed is limited by the frame rate of the camera that captures the patterns.We propose a compact and cost-effective ultrafast wavemeter based on multimode and multicore fibers,which employs spectral-spatial-temporal mapping.The speckle patterns generated by multimode fibers enable spectral-to-spatial mapping,which is then sampled by a multicore fiber into a pulse sequence to implement spatial-to-temporal mapping.A high-speed single-pixel photodetector is employed to capture the pulse sequence,which is analysed using a multilayer perceptron to estimate the wavelength.The feasibility of the proposed wavelength estimation method is experimentally verified,achieving a measurement rate of 100 MHz with a resolution of 2.7 pm in a 1 nm operation bandwidth.
文摘A dual system and dual wavelength spectrophotometry (DSDWS) used to simultaneously determine Zr and Hf were proposed. Zr(Hf)-XO-CIMAB and Zr(Hf)-CAB-CDMAA-Triton X-100 were chosen as a pair of chromophoric systems. The difference of chromophoric behaviours between Zr and Hf is increased by the addition of hydrogen peroxide as masking agent and by adjustment of acidity. The apparent molar absorptivities of Zr and Hf are 2.0×105 and 5.0×104 L·mol-1·cm-1 respectively. The procedure is simple and rapid.
基金financially supported by the National Natural Science Foundation of China (NSFC) (Grant No. 62275151)
文摘Spectroscopy is the basic tool for studying molecular physics and realizing biochemical sensing.However,it is challenging to realize sub-femtometer resolution spectroscopy over broad bandwidth.Broadband and high-resolution spectroscopy with calibrated optical frequency is demonstrated by bridging the fields of speckle pattern and electro-optic frequency comb.A wavemeter based on a whispering-gallery-mode barcode is proposed to link the frequencies of a probe continuous-wave laser and an ultrastable laser.The ultrafine electro-optic comb lines are generated from the probe laser to record spectrum of sample with sub-femtometer resolution.Measurement bandwidth is a thousandfold broader than comb bandwidth,by sequentially tuning the probe laser while its wavelength is determined.This approach fully exploits the advantages of two fields to realize 0.8-fm resolution with a fiber laser and 80-nm bandwidth with an external cavity diode laser.The spectroscopic measurements of an ultrahigh Q-factor cavity and gas molecular absorption are experimentally demonstrated.The compact system,predominantly constituted by few-gigahertz electronics and telecommunication components,shows enormous potential for practical spectroscopic applications.
