Polarization-Independent All-Fibre Comb Filter with Dynamically Halved Channel Spacing

A polarization-independent all-fibre comb filter with dynamically halved channel spacing is proposed. The filter is based on high-birefringent fibre Sagnac interferometers and its channel spacing can be dynamically halved by turning on an optical switch. A good agreement between the numerical simulation and the experimental results is achieved.     

Flat amplitude multiwavelength Brillouin–Raman random fiber laser with a half-open cavity

In this paper, we experimentally demonstrate a novel configuration of multiwavelength Brillouin–Raman random fiber laser (MBRRFL) utilizing a half-open cavity. The laser resonator is formed by fiber loop mirror at the Brillouin pump (BP) side and random distributed Rayleigh backscattering in a 10 km dispersion compensating fiber. As a result, we are able to obtain a flat amplitude bandwidth of 16.8 nm from 1,550.0 to 1,566.8 nm built-in 210 uniform Brillouin Stokes lines with 0.08 nm spacing and an average OSNR of 13.5 dB. We also studied the influence of BP power and wavelength on the MBRRFL’s performance. Furthermore, comparing with the open cavity configuration, the discrepancies in power level and linewidth between neighboring channels are overcome by using the half-open cavity.     

Laser Tracking and Pointing at a Target with Stimulated Brillouin Scattering

Laser tracking and pointing at a simulated moving target in atmosphere 1.27 km away is realized experimentally,in which stimulated Brillouin scattering (SBS) phase conjugation technology and velocity compensation mirror are used. Only if the angle between the SBS phase conjugation laser and the illumination laser is smaller than the atmosphere isoplanatic angle ψo, is the wave-front aberration of laser beam produced by atmospheric turbulence compensated for in real time. This experiment was carried out with horizontal ranges 1.27km at 50m height above the ground, and Nd: YA G lasers are used. By changing the angle of a velocity compensation mirror reflecting the SBS phase conjugation laser to the simulated target, simulated targets with different moving velocities are tracked and pointed by the laser beam. The spot and energy distribution of illumination laser spot and SBS phase conjugation laser are recorded. The energy back to target is up to 75 mJ. The SBS phase conjugation laser spot shows that it is focused at the simulated moving target within a small area.     

Linewidth of Semiconductor-Optical Fiber Ring External Cavity Laser with Tunable Optical Fiber F-P Cavity

１ＩｎｔｒｏｄｕｃｔｉｏｎＮａｒｏｗｌｉｎｅｗｉｄｔｈｔｕｎａｂｌｅｓｉｎｇｌｅｆｒｅｑｕｅｎｃｙｓｅｍｉｃｏｎｄｕｃｔｏｒｌａｓｅｒｓａｒｅｎｅｄｆｏｒａｐｐｌｉｃａｔｉｏｎｓｉｎｃｏｈｅｒｅｎｔｃｏｍｍｕｎｉｃａｔｉｏｎ，ｃｏｈｅｒｅｎｔｄｅ...     

Blue Up-Conversion Fibre Laser Pumped by a ll20-nm Raman Fibre Laser

A Tm^3 -doped ZrF4-BaF2-LaF3 AlF3-NaF (ZBLAN) fibre up-conversion laser pumped by a 1120-nm Raman fibre laser is demonstrated with blue output power levels up to 116mW. For the output mirror with 80^ reflectivity, the slope efficiency is about 15%, the optical-to-optical conversion efficiency is 11%, and the maximum un-saturated output power is 116mW. For 60% reflectivity, the slope efficiency is about 18% and the opticalto-optical conversion efficiency is 12%, whilst the maximum saturated output power is about 80roW due to the existence of photo-degradation effect in Tm^3 doped ZBLAN glass fibre.     

A tunable multi-wavelength Brillouin–erbium fiber laser with fourfold Brillouin frequency spacing

We have experimentally demonstrated a tunable multi-wavelength Brillouin–erbium fiber laser with over 40 GHz spacing utilizing two cascaded double Brillouin-frequency-spacing cavities. In this laser configuration, two segments of 25 km-long single-mode fibers are used as Brillouin gain medium in each ring cavity, and a segment of 8 m-long erbium-doped fiber with 980 nm pump is employed to amplify Brillouin pump (BP). At BP wavelength of 1550 nm, BP power of 8.3 dBm (6.8 mW) and the maximum 980 nm pump power of 27.78 dBm (600 mW), seven output channels with fourfold Brillouin-frequency spacing, and the tuning range of 15 nm from 1545 to 1560 nm are achieved. The proposed multi-wavelength Brillouin–erbium fiber laser has wide applications, such as in microwave signal generation and optical communications.     

-switched Yb Doped Fiber Ring Laser with a M-Z Interferometer

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｑ ｓｗｉｔｃｈｅｄｌａｓｅｒｓａｒｅａｔｔｒａｃｔｉｖｅｌａｓｅｒｓｏｕｒｃｅｓｆｏｒｒａｎｇｉｎｇ ,ａｌｔｉｍｅｔｒｙ ,ｌｉｄａｒ,ａｎｄｏｔｈｅｒａｐｐｌｉｃａｔｉｏｎｓｒｅｑｕｉｒｉｎｇｈｉｇｈｅｎｅｒｇｉｃ ｐｕｌｓｅｓ .Ｑ ｓｗｉｔｃｈｅｄｆｉｂｅｒｌａｓｅｒｓｙｓｔｅｍｓｂａｓｅｄｏｎｓｉｎｇｌｅ ｍｏｄｅｒａｒｅ ｅａｒｔｈｄｏｐｅｄｆｉｂｅｒｓｈａｖｅａｔｔｒａｃｔｅｄｇｒｅａｔｉｎｔｅｒｅｓｔｂｅｃａｕｓｅｔｈｅｙｃａｎｂｅｕｓｅｄａｓｃｏｍｐａｃｔ,…     

Compensations of Stimulated Brillouin Scattering Effect with Stimulated Raman Effect in Distributed EDFA

ＣｏｍｐｅｎｓａｔｉｏｎｓｏｆＳｔｉｍｕｌａｔｅｄＢｒｉｌｌｏｕｉｎＳｃａｔｔｅｒｉｎｇＥｆｆｅｃｔｗｉｔｈＳｔｉｍｕｌａｔｅｄＲａｍａｎＥｆｆｅｃｔｉｎＤｉｓｔｒｉｂｕｔｅｄＥＤＦＡＬＩＨｏｎｇ；ＣＨＥＮＨａｉｊｕａｎ；ＹＡＮＧＸｉａｎｇｌｉｎ（Ｄ...     

Microwave Photonic Signal Down‐Conversion Using a Novel Two‐Frequency Bragg Grating Based Brillouin Fiber Laser

A simple technique using a novel twofrequency Bragg grating based Brillouin fiber laser to downconvert high frequency microwave photonic signals is presented. The mechanism of the Brillouin fiber laser and the principle of this technique for microwave photonic signal downconversion are analyzed. The 12GHz microwave photonic signals are experimentally downconverted to 1.13GHz IF signal with the technique.     

Synchronously Pumped Mode-Locked 1.89 μm Tm-Doped Fiber Laser with High Detuning Toleration

We propose and demonstrate a synchronously pumped mode-locked Tm-doped fiber(TDF) laser without any extra mode-locking elements. Pumped by a 1.56 μm pulse fiber laser, the TDF laser generates 1.17 ps pulses with a spectral width of 9.7 nm and a repetition rate of 9.33 MHz. The emission wavelength is tunable along with the cavity length detuning in a wide range of 3 mm. The high detuning toleration is beneficial to achieve high temperature and vibration stability in all-fiber configuration lasers.     

Electrostatic vibration energy harvester with 2.4-GHz Cockcroft–Walton rectenna start-up

In this paper, we propose the design, fabrication and experiments of a macro-scale electrostatic vibration energy harvester (e-VEH), pre-charged wirelessly for the first time with a 2.4-GHz Cockcroft–Walton rectenna. The rectenna is designed and optimized to operate at low power densities and provide high voltage levels: 0.5 V at 0.76 μW/cm² and 1 V at 1.53 μW/cm². The e-VEH uses a Bennet doubler as a conditioning circuit. Experiments show a 23-V voltage across the transducer terminal, when the harvester is excited at 25 Hz by $1.5g$ of external acceleration. An accumulated energy of 275 μJ and a maximum available power of 0.4 μW are achieved.     

A New Neodymium∶Phosphate-glass Single Transverse Mode Fiber Laser with Double Clad Geometry

１ＩｎｔｒｏｄｕｃｔｉｏｎＷｉｔｈｓｉｎｇｌｅｍｏｄｅｆｉｂｅｒｌａｓｅｒｓ，ｉｔｉｓｑｕｉｔｅｅａｓｙｔｏｇｅｎｅｒａｔｅｅｘｃｅｌｅｎｔｑｕａｌｉｔｙｂｅａｍｏｆｓｉｎｇｌｅｔｒａｎｓｖｅｒｓｅｍｏｄｅ［１，２］，ｂｕｔｔｈｅｙｈａｖｅｂｅｅｎｇ...     

A High Efficiency Yb~(3 )-doped Fiber Ring Cavity Laser with Narrow Line-width

1　Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｔｏｄａｙ ,ｔｈｅＥｒ3 ｄｏｐｅｄｆｉｂｅｒｌａｓｅｒａｎｄｔｈｅａｍｐｌｉｆｉｅｒａｒｅｗｉｄｅｌｙｕｓｅｄｉｎｔｈｅｆｉｅｌｄｏｆｏｐｔｉｃａｌｃｏｍｍｕｎｉｃａｔｉｏｎａｎｄｏｔｈｅｒｆｉｅｌｄｓ.ＴｈｅＹｂ3 ｄｏｐｅｄｆｉｂｅｒｌａｓｅｒａｎｄａｍｐｌｉｆｉｅｒｈａｖｅｂｅｅｎｉｎｖｅｎｔｅｄａｎｄｕｓｅｄｉｎｍａｎｙｉｍｐｏｒｔａｎｔｆｉｅｌｄｓｔｏｏ ,ａｎｄｔｈｅｙａｒｅａｔｔｒａｃｔｉｎｇｍｏｒｅａｎｄｍｏｒｅａｔｔｅｎｔｉｏｎ[1～ 4 ] .Ｃｏｍｐａｒ…     

Passively Q-Switched Yb-Doped Fiber Laser Operating at 1.06μm with Two-Dimensional Silver Nanoplate as Saturable Absorber

A two-dimensional silver nanoplate is prepared with the seed-mediated growth method and is used for achieving pulse fiber laser operation. By controlling the dimension parameters of the silver nanoplate, the surface plasmon resonance absorption peak of the material is successfully adjusted to 1068 nm. Based on the silver nanoplate as a saturable absorber, a passively Q-switched Yb-doped fiber laser operating at 1062 nm is demonstrated. The maximum average output power of 3.49 mW is obtained with a minimum pulse width of 1.84 ps at a pulse repetition rate of 65.7 kHz, and the corresponding pulse energy and peak power are 53.1 nJ and 28.8 mW, respectively.     

A 0．98μm Laser Diode Pumped Erbium－Doped Fiber Amplifier with 40nm Bandwidth

Ａ０．９８μｍＬａｓｅｒＤｉｏｄｅＰｕｍｐｅｄＥｒｂｉｕｍ－ＤｏｐｅｄＦｉｂｅｒＡｍｐｌｉｆｉｅｒｗｉｔｈ４０ｎｍＢａｎｄｗｉｄｔｈ￥ＬＩＪｉｎｇｈｕｉ；ＰＥＮＧＪｉａｎｇｄｅ；ＪＩＡＮＧＸｉｎ；ＹＡＯＭｉｎｙｕ；ＷＵＧｅｎｇｓｈｅｎｇ；ＦＡＮＣｈｏ...     

Transform method in resonance Raman scattering with quadratic Franck–Condon and Herzberg–Teller interactions

A new method of considering quadratic vibronic interactions and deviations from the Condon approximation in resonance Raman scattering (RRS) is proposed. The method is used for the generalization of the transform law between absorption and Raman excitation profiles, derived earlier for a basic model. In the case of arbitrary mixing of modes with similar frequencies, a simple generalization of the transform law for first-order RRS is obtained. For an arbitrary change of frequencies without mode mixing the transform law for the nth-order RRS is given. The equations are valid for an arbitrary number of modes and also take temperature effects into account.     

Ⅲ–Ⅴ/Si Hybrid Laser Array with DBR on Si Waveguide

We report an eight-channel silicon evanescent laser array operating at continuous wave under room temperature conditions using the selective-area metal bonding technique.The laser array is realized by evanescentl.y coupling the optical gain of InGaAsP multi-quantum wells to the silicon waveguides of varying widths and patterned with distributed Bragg reflector gratings.The lasers have emission peak wavelengths in a range of 1537-1543 nm with a wavelength spacing of about 1.0 nm.The thermal impedances Z_T of these hybrid lasers are evidently lower than those DFB counterparts     

Realizing 20 Gbits OTDM Transmission over 50km Truewave Fiber with Dispersion Compensation

Ｉｎｔｒｏｄｕｃｔｉｏｎ　　Ｔｈｅｒｅａｒｅｔｗｏｍｅｔｈｏｄｓｔｏｅｎｈａｎｃｅｔｈｅｃａｐａｃｉｔｙｏｆｔｈｅｔｒａｎｓｍｉｓｓｉｏｎｓｙｓｔｅｍ：ｏｐｔｉｃａｌｔｉｍｅｄｉｖｉｓｉｏｎｍｕｌｔｉｐｌｅｘｉｎｇ（ＯＴＤＭ）ａｎｄｏｐｔｉｃａｌｗａｖｅｌｅｎｇｔｈｄｉｖｉｓｉｏｎｍｕｌｔｉｐｌｅｘｉｎｇ（ＷＤＭ）．ＯＴＤＭｉｓｂｅｉｎｇｗｉｄｅｌｙｒｅｓｅａｒｃｈｅｄｂｅｃａｕｓｅｏｆｓｏｍｅｖｉｒｔｕｅｓｉｎｏｐｔｉｃａｌｎｅｔｗｏｒｋｓ［１～４］．ＯＴＤＭｗｉｔｈｔｈｅｓｉｎｇｌｅｃｈａｎ…