A modified multiwavelength actively mode-locked fiber ring laser is proposed and experimentally demonstrated. In this kind of laser, stable multiwavelengths lasing is achieved by integrating cascaded sampled fiber Bra...A modified multiwavelength actively mode-locked fiber ring laser is proposed and experimentally demonstrated. In this kind of laser, stable multiwavelengths lasing is achieved by integrating cascaded sampled fiber Bragg gratings(SFBGs) into the laser cavity. To implement actively mode-locking technique, a double-ring cavity configuration is used to assure that the cavity lengths for all wavelengths lasing are identical. Thus, simultaneous mode locking of all wavelengths has been successfully achieved by using the same mode-locking signal.展开更多
A novel and simple fiber grating sensor based on high-duty-cycle sample fiber Bragg grating is proposed and demonstrated experimentally. This type of sensor can measure strain and temperature simultaneously with merit...A novel and simple fiber grating sensor based on high-duty-cycle sample fiber Bragg grating is proposed and demonstrated experimentally. This type of sensor can measure strain and temperature simultaneously with merits of low cost, high sensitivity and immunity to electro- magnetic interference. The sensor has an accuracy of 20 με and 0.8 ℃ over a strain range of 500～1 500με and a temperature range of 5～36 ℃ under experimental conditions.展开更多
One of the most basic characteristics of photonic crystal is frequency band gap. When defects are introduced into the periodic photonic crystal, a number of defect modes appear in the stop band.In this paper, we explo...One of the most basic characteristics of photonic crystal is frequency band gap. When defects are introduced into the periodic photonic crystal, a number of defect modes appear in the stop band.In this paper, we exploit transfer matrix method based on photonic crystal theory, and assume the sampled fiber Bragg grating as one-dimensional dual photonic crystal with a large size defect. Characteristics of the sampled fiber Bragg grating are analyzed. Experimental results show that the sampled fiber Bragg grating has many reflective peaks. Its reflectivity, center wavelength, reflective peak intervals and band width all change with the grating parameters, including grating length, duty ratio of the material with high dielectric constant, and index modulation depth and period. Results agree with the conventiona1 couple mode theory which can be used when analyzing other characteristics of the sampled fiber Bragg grating or applying it into practice.展开更多
A novel dynamic optical add-drop multiplexer(OADM) scheme using tunable sampled fiber Bragg gratings(SFBG) by Vernier effect is firstly proposed. In this scheme, broad wavelength tuning range is achieved by only sligh...A novel dynamic optical add-drop multiplexer(OADM) scheme using tunable sampled fiber Bragg gratings(SFBG) by Vernier effect is firstly proposed. In this scheme, broad wavelength tuning range is achieved by only slightly adjusting the SFBG, the wavelength tuning of OADM will be faster than traditional dynamic OADM.展开更多
On the basis of the coherence theory a new method is presented to analyze the sampled chirped fiber gratings (SCFG). With this method, more results on the SCFG are obtained, including not only the characteristics of r...On the basis of the coherence theory a new method is presented to analyze the sampled chirped fiber gratings (SCFG). With this method, more results on the SCFG are obtained, including not only the characteristics of reflectivity, transmission and time delay, but also the simplified reflectivity formula, the channel's number, wavelength spacing and channel's bandwidth. Therefore, this method is more systematic and perfect than the usual transfer matrix method and can well guide the design of the SCFG.展开更多
Multi-wavelength fiber ring laser based on the semiconductor optical amplifier(SOA)with sampled fiber Bragg grating(SFBG)in a Sagnac loop interferometer as the wavelength-selective filter is proposed.Four lasing wavel...Multi-wavelength fiber ring laser based on the semiconductor optical amplifier(SOA)with sampled fiber Bragg grating(SFBG)in a Sagnac loop interferometer as the wavelength-selective filter is proposed.Four lasing wavelengths with 1.8 nm spacing have been generated stably at room temperature.The proposed laser has the advan-tages such as removal of the high-cost circulator,flexibility in channel-spacing tuning,and simple all-optical fiber configuration,which has potential applications in high-capacity wavelength-division-multiplexed(WDM)systems and mechanical sensors.展开更多
Sampled fiber grating is a special superstructure fiber Bragg grating with a wide range of applications in many fields.In this work,based on drawing tower in-line fabrication system,a new preparation method of the sam...Sampled fiber grating is a special superstructure fiber Bragg grating with a wide range of applications in many fields.In this work,based on drawing tower in-line fabrication system,a new preparation method of the sampled fiber grating is proposed and experimentally demonstrated.Experimental result shows that the obtained sampled fiber gratings possess dense reflection spectra,with a minimum reflection peak interval of only 0.09 nm.This method exhibits promising application prospect in the fabrication of the high-quality sampled fiber grating.On the other hand,the spectral characteristics of the sampled fiber grating are analyzed when the sub-grating is affected by the external physical quantities such as,in this paper,strain.Wavelength shift and intensity change in the reflection peak of the spectra indicate that the grating is affected differently by micro strains,due to the different spatial positions along the axis of the sampled fiber grating.This work is aimed at exploring the potential applications of the sampled fiber grating in quasi-distributed micro-area sensing with the millimeter level.展开更多
文摘A modified multiwavelength actively mode-locked fiber ring laser is proposed and experimentally demonstrated. In this kind of laser, stable multiwavelengths lasing is achieved by integrating cascaded sampled fiber Bragg gratings(SFBGs) into the laser cavity. To implement actively mode-locking technique, a double-ring cavity configuration is used to assure that the cavity lengths for all wavelengths lasing are identical. Thus, simultaneous mode locking of all wavelengths has been successfully achieved by using the same mode-locking signal.
文摘A novel and simple fiber grating sensor based on high-duty-cycle sample fiber Bragg grating is proposed and demonstrated experimentally. This type of sensor can measure strain and temperature simultaneously with merits of low cost, high sensitivity and immunity to electro- magnetic interference. The sensor has an accuracy of 20 με and 0.8 ℃ over a strain range of 500～1 500με and a temperature range of 5～36 ℃ under experimental conditions.
文摘One of the most basic characteristics of photonic crystal is frequency band gap. When defects are introduced into the periodic photonic crystal, a number of defect modes appear in the stop band.In this paper, we exploit transfer matrix method based on photonic crystal theory, and assume the sampled fiber Bragg grating as one-dimensional dual photonic crystal with a large size defect. Characteristics of the sampled fiber Bragg grating are analyzed. Experimental results show that the sampled fiber Bragg grating has many reflective peaks. Its reflectivity, center wavelength, reflective peak intervals and band width all change with the grating parameters, including grating length, duty ratio of the material with high dielectric constant, and index modulation depth and period. Results agree with the conventiona1 couple mode theory which can be used when analyzing other characteristics of the sampled fiber Bragg grating or applying it into practice.
文摘A novel dynamic optical add-drop multiplexer(OADM) scheme using tunable sampled fiber Bragg gratings(SFBG) by Vernier effect is firstly proposed. In this scheme, broad wavelength tuning range is achieved by only slightly adjusting the SFBG, the wavelength tuning of OADM will be faster than traditional dynamic OADM.
文摘On the basis of the coherence theory a new method is presented to analyze the sampled chirped fiber gratings (SCFG). With this method, more results on the SCFG are obtained, including not only the characteristics of reflectivity, transmission and time delay, but also the simplified reflectivity formula, the channel's number, wavelength spacing and channel's bandwidth. Therefore, this method is more systematic and perfect than the usual transfer matrix method and can well guide the design of the SCFG.
基金supported by the National“863” Project of China(2007AA01Z258)the National Natural Science Foundation of China(60771008)+2 种基金Program for New Century Excellent Talents in University(NCET-06-0076)Beijing Natural Science Foundation(4082024)the Beijing Jiaotong University Foundation(2006XM003)
文摘Multi-wavelength fiber ring laser based on the semiconductor optical amplifier(SOA)with sampled fiber Bragg grating(SFBG)in a Sagnac loop interferometer as the wavelength-selective filter is proposed.Four lasing wavelengths with 1.8 nm spacing have been generated stably at room temperature.The proposed laser has the advan-tages such as removal of the high-cost circulator,flexibility in channel-spacing tuning,and simple all-optical fiber configuration,which has potential applications in high-capacity wavelength-division-multiplexed(WDM)systems and mechanical sensors.
基金This work was supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.61290311 and 61735013)the Major Scientific and Technological Innovation Project in Hubei Province(Grant No.2015AAA001).
文摘Sampled fiber grating is a special superstructure fiber Bragg grating with a wide range of applications in many fields.In this work,based on drawing tower in-line fabrication system,a new preparation method of the sampled fiber grating is proposed and experimentally demonstrated.Experimental result shows that the obtained sampled fiber gratings possess dense reflection spectra,with a minimum reflection peak interval of only 0.09 nm.This method exhibits promising application prospect in the fabrication of the high-quality sampled fiber grating.On the other hand,the spectral characteristics of the sampled fiber grating are analyzed when the sub-grating is affected by the external physical quantities such as,in this paper,strain.Wavelength shift and intensity change in the reflection peak of the spectra indicate that the grating is affected differently by micro strains,due to the different spatial positions along the axis of the sampled fiber grating.This work is aimed at exploring the potential applications of the sampled fiber grating in quasi-distributed micro-area sensing with the millimeter level.
