Chunliu Zhao

Efficient multi-wavelength fiber laser operating in L-band

In this paper, an efficient L-band multi-wavelength erbium-doped fiber ring laser is demonstrated by recycling backward 1550 nm band amplified spontaneous emission as secondary pump source for the unpumped EDF section. The lasing threshold is reduced and the slope efficiency is improved. A piece of multimode fiber is used as a spatial mode-beating filter. By adjusting the polarization state of the light, the number of lasing wavelength and their spaces are controlled. In dual-wavelength laser, the power of each channel is 4 mW with 40 dB side-mode-suppression-ratio.

Novel Fiber Grating Sensing Technique Based on the Torsion Beam

A novel fiber grating sensing technology based on the torsion beam is reported for the first time. The Bragg wavelength change is linear with the torsional angle and the torque. The fiber Bragg grating (FBG) is firmly mounted on the surface of the torsion beam with a determinate angle along the direction of the axes of the torsion beam. The range of the torsional angle is between -45 degree(s) and +45 degree(s). The sensing sensitivity of the torsional angle is up to 11.534 degree/nm and that of the torque is up to 0.1595 Nm/nm, respectively. The formulas have been derived theoretically and the experimental results basically accord with the theoretical ones. This technology has many advantages, such as two dimensional tuning, the high sensitivity, the good repetitiveness and no chirping for the torsional angle within the range -45 degree(s) and +45 degree(s), etc. It has potential applications in the area of the fiber sensing, the fiber communication and laser technology.

Wavelength tunable linear cavity Er-doped fiber laser operating in L-band

A novel method, which utilizes amplified spontaneous emission (ASE) as a secondary pump source, is presented for implanting a linear cavity erbium-doped fiber laser operating in L-Band. The output wavelength tuned from 1583nm to 1600nm, about 17nm tuning range, was obtained in the experiment and the stability of the laser is very good.

Wavelength tuning fiber ring mode-locking laser by tunable chirped fiber Bragg grating

Utilizing large dispersion of a chirped fiber Bragg rating (CFBG), a wavelength tunable mode-locked fiber ring laser was obtained in the band width of the CFBG. Compared with the structure included dispersion compensating fiber, the supermode noise and enviment influence were suppressed. The 2.5GHz pulses were generated.

Wavelength-tunable actively mode-locked fiber ring laser with fiber grating

Using the characteristics of precise wavelength-selected and special tuning method of fiber grating, stable pulses train with a wavelength-tunable range of 8 nm at a repetition rate of 2.5 GHZ has been achieved in an actively mode-locked erbium-doped fiber ring laser.

Novel four-wavelength erbium-doped fiber laser as multichannel source in WDM system

A novel four-wavelength all-fiber laser based on fiber Bragg gratings is presented. The four wavelengths are 1555.8, 1556.6, 1557.4 and 1558.s nm, respectively. Each output laser is < 0.3 nm in line-width and > 1 mW in power. The suppression ratio between adjacent wavelengths is > 30 dB. The laser was applied in a wavelength division multiplexing system and the 100 km transmission of 1.2 Gb/s nonreturn-to-zero code, 1.2 Gb/s return-to-zero, 2.5 GHz analogue signal and 5 GHz analogue signal was realized with it.

Multiwavelength fiber linear-cavity laser in L-band

Without any stabilizing equipment, a multi-wavelength fiber linear cavity laser in L-band was obtained at the room temperature. The cavity was formed by two linear fiber loops. Utilizing the birefringence of the single mode fiber, we can make the reflectivity of these fiber-loops vary periodically with the wavelength. Two polarization controllers (PCs) were inserted into fiber loops. By changing the states of PCs, the number of the lasing wavelengths and wavelength spaces can be controlled.

21-nm-range wavelength-tunable L-band Er-doped fiber linear-cavity laser

A novel method, which utilizes amplified spontaneous emission (ASE) as a secondary pump source, is presented for implanting a linear cavity erbium-doped fiber laser operating in L-Band. The output wavelength tuned from 1566 nm to 1587 nm, about 21 nm tuning range, was obtained in the experiment and the stability of the laser is very good.

Novel fiber Bragg grating displacement sensor

A new displacement measuring scheme based on simply supported beam is reported and demonstrated. The theoretical formula is derived and the experimental results are given. This device has many characteristics, such as simple structure, high sensitivity and good linearity. It is promising to be used into in-process displacement measurement.

Continuous-tuning mode-locked fiber ring laser using a F-P LD

Highly stable single wavelength pulse train was generated in a fiber ring laser by using a F-P semiconductor laser diode simultaneously as the modulator and the tunable filter. Compared with systems using M-Z interferometer modulator, this experimental setup need lower gain to produce stable mode-locked pulse due to the lower cavity loss. As a result, continuous wavelength tunable range up to 1nm was achieved by changing the LD temperature. And the frequency pulse with pulse-width 50ps was 2GHz.