1．OPTICS EXPRESS, Vol. 17, No. 12, 8 June 2009 pp. 9549-9557

Dissipative soliton evolution in ultra-large normal-cavity-dispersion fiber lasers

Xueming Liu

State Key Laboratory of Transient Optics and Photonics,

Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China

Email: liuxm@opt.ac.cn

Abstract: Dissipative soliton (DS) evolution in passively mode-locked fiber lasers with ultra-large net-normal-dispersion (as large as 1 ps2) is investigated. The proposed DS laser operates on three statuses with respect to the pump power. The DS laser works on a status that is similar to an all-normal-dispersion laser when the pump power is low, whereas it creates a new type of pulses exhibited as the trapezoid-spectrum profile when the pump power is large. The laser cavity emits the unstable pulses between the above two statuses. The cubic–quintic Ginzburg–Landau equation can serve to qualitatively explain our experimental observations.

2. Optics Letters, Vol. 34, Issue 6, pp. 791-793　　　 

All-optical switching application of germano-silicate optical fiber incorporated with Ag nanocrystals

Aoxiang Lin, Xueming Liu, Pramod R. Watekar, Wei Zhao, Bo Peng, Chuandong Sun, Yishan Wang, and Won-Taek Han

Abstract:Ag-nanocrystal-incorporated germano-silicate optical fiber with high resonant nonlinearity was fabricated by using modified chemical vapor deposition and solution doping techniques. An all-optical signal switching application based on cross-phase modulation was demonstrated in the cascaded long-period fiber gratings. Pumped with 499 nm argon laser, all-optical signal gating of the π-phase shift was achieved with low pump intensities of less than 7.64 GW/cm2.

3. November 15, 2009 / Vol. 34, No. 22 / OPTICS LETTERS 3553

Phase-shift extraction for generalized

phase-shifting interferometry

Peng Gao,1,2,3,4 Baoli Yao,3,* Norbert Lindlein,1 Klaus Mantel,2

Irina Harder,2 and Eduard Geist1

1Institute of Optics, Information and Photonics, University of Erlangen, Erlangen, Germany

2Max-Planck-Institute for the Science of Light, Germany

3State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics,

Chinese Academy of Sciences, China

4Graduate School of the Chinese Academy of Sciences, Beijing 100039, China

*Corresponding author: yaobl@opt.ac.cn

 

Abstract: A simple algorithm for blind extraction of phase shifts is proposed for generalized phase-shifting interferometry from only three interferograms. Based on the statistical property of the object wave, the algorithm calculates approximately the involved phase shifts as initial values. The extraction is further improved by an iterative method, considering the fact that the closer the phase shifts approach their real values, the more uniform the reconstructed reference wave will become. The feasibility of this algorithm is demonstrated by both simulation and experiment.

 

4. Optics Communications 282 (2009) 1858–1860

Stacking chirped pulse optical parametric amplification

Hongjun Liu *, Hongying Wang, Xiaoli Li, Yishan Wang, Wei Zhao, Chi Ruan

Abstract: Stacking chirped pulse optical parametric amplification based on a home-built Yb3+-doped mode-locked fiber laser and an all-fiber pulse stacker has been demonstrated. Energic 11 mJ shaped pulses with pulse duration of 2.3 ns and a net total gain of higher than 1.1 _ 107 at fluctuation less than 2% rms are achieved by optical parametric amplification pumped by a Q-switched Nd:YAG frequency-doubled laser, which provides a simple and efficient amplification scheme for temporally shaped pulses by stacking chirped pulse.

5. Optics Communications 282 (2009) 4527–4531

Numerical analyses of splice losses of photonic crystal fibers

Zhongnan Xu a,b, Kailiang Duan b,*, Zejin Liu a, Yishan Wangb, Wei Zhao b

a College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073, China

b State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710119, China

Abstract: Splice losses between a photonic crystal fiber (PCF) and a single mode fiber (SMF) or a PCF are numerically investigated by using finite element method (FEM) with the circular perfectly matched layer (PML). Results show that the splice loss between a SMF and a PCF with air holes completely collapsed can reach many times of that between a SMF and a PCF without air-hole collapse. We calculate the rotation losses between two identical PCFs of three kinds: large mode area, polarization maintaining and grapefruit. It is shown that for the large mode area PCF and the grapefruit PCF, the rotation losses are sensitive to the wavelength when the rotation angle is larger than zero degree. The non-circular mode field distribution is the main source of the rotation loss.

 

6.JOURAl OF APPLIED PHYSICS 105.043518(2009)

Intersubband optical absorption in a step asymmetric semiconductor quantum well driven by a terahertz field

Hai-Yan Zhu,1,2,a Tong-Yi Zhang,1 and Wei Zhao1

1State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision

Mechanics, Chinese Academy of Sciences, 17 Xinxi Road, Xi’an 710119, People’s Republic of China

2Graduate School of the Chinese Academy of Sciences, Beijing 100039, People’s Republic of China

Abstract: The nonlinear optical absorption in a three-subband step asymmetric semiconductor quantum well driven by a strong terahertz (THz) field is investigated theoretically by employing the intersubband semiconductor-Bloch equations. We show that the optical absorption spectrum strongly depends on the intensity, frequency, and phase of the pump THz wave. The strong THz field induces THz sidebands and Autler-Townes splitting in the probe absorption spectrum. Varying the pump frequency can bring not only the new absorption peaks but also the changing of the energy separation of the two higher-energy levels. The dependence of the absorption spectrum on the phase of the pump THz wave is also very remarkable.

 

7.J.Opt.Soc.Am.B/Vol.26,No.12/2009

Trapping of low-refractive-index particles with

azimuthally polarized beam

Fei Peng,1,2 Baoli Yao,1,* Shaohui Yan,1 Wei Zhao,1 and Ming Lei3

1State Key Laboratory of Transient Optics and Photonics,

Xi’an Institute of Optics and Precision Mechanics, Xi’an 710119, China

2Graduate School of the Chinese Academy of Sciences, Beijing 100039, China

3College of Life Science and Shaanxi Key Laboratory of Molecular Biology for Agriculture,

Northwest Agriculture and Forestry University, Yangling 712100, China

*Corresponding author: yaobl@opt.ac.cn

Abstract: Azimuthally polarized beams, focused by a high-numerical-aperture (NA) objective lens, form a hollow intensity distribution near the focus, which is appropriate for trapping low-refractive-index particles, in contrast to common linearly polarized or radially polarized beams. In this paper, the field distribution of the azimuthally polarized beam focused by a high-NA objective is described by the vectorial diffraction integral, and then the radiation forces on spherical particles with different parameters such as radius and refractive index are calculated by the T-matrix method. Numerical results show that the azimuthally polarized beam not only can steadily trap low-refractive-index particles at the focus center but also can trap multiple high-refractive-index particles around the focus center by virtue of the hollow-ring configuration. The range of the sizes of lowrefractive-index particles that can be trapped steadily are presented, corresponding to different parameters such as the NA of the objective and the relative refractive index, based on which the NA of the objective can be selected to trap the appropriate size of particles.

8. Optics Letters, Vol. 34, Issue 17, pp. 2676-2678　　　  

 Self-collimating photonic-crystal wave plates

Wenfu Zhang, Jihong Liu, Wei-Ping Huang, and Wei Zhao

Abstract: We present theoretical results of quarter- and half-wave plates based on two-dimensional photonic crystal that has a polarization-independent self-collimating effect. The designed low-order wave plates have achromatic characteristic with high phase accuracy of +/-0.01π in the normalized frequency range 0.273-0.281a/λ, which is about 45 nm in the telecommunication band (around 1550 nm). Profiting from the self-collimating guiding mechanism, the wave plates (even the relative high-order ones) have low beam divergence and transmission loss. In addition, on the basis of the formed birefringence effect, a method for designing high-order wave plates is proposed. The wave plates presented in this Letter have potential applications in future photonic integrated circuits.

9. JOSA B, Vol. 26, Issue 10, pp. 1845-1851　　   

Polarization bandpass filter based on one-dimensional photonic crystal heterostructure

Wenfu Zhang, Jihong Liu, Wei-Ping Huang, and Wei Zhao

Abstract:A new kind of polarization bandpass filters (P-BPFs), which fulfill the functions of high reflectivity for one polarization and high transmittance in the passband for the other, are proposed. The P-BPFs consist of a stack of two one-dimensional (1D) photonic crystals (PCs) that are referred to as 1D PC heterostructures. The essential function of P-BPFs is realized by making the first transmitted peak near the photonic bandgap edges of one PC coincide with that of the other PC. Based on this method, three kinds of filters have been designed and discussed in detail: an isotropic 1D PC single-polarization bandpass filter (SP-BPF) at oblique incidence with a narrow passband for TM polarization and a broadened stop band for TE polarization, an anisotropic 1D PC SP-BPF at normal incidence with a narrow passband for TE polarization and a broadened stop band for TM polarization, and an anisotropic 1D PC double-polarization bandpass filter (DP-BPF) at oblique incidence with a spectral separated narrow passband for both polarizations, respectively. The filters can be fabricated by a lot of coating methods and integrated easily with other photonic components.

10. Microwave and Optical Technology Letters 2009,Vol.51,No.1,63-

 Experimental investigation into femtosecond fiber ring laser with passive mode locking

:Xiaoping Xie, Jian-Guo Zhang , Yu Wen, Wei Zhao

Abstract:A passively mode-locked Er3+-doped fiber ring laser is experimentally investigated, with the emphasis on its practical design by considering the effects of ring cavity length, pumping light power, and optical amplification on the femtosecond optical pulses obtained. It is shown that the designed fiber ring laser can operate at the center wavelength of 1550 nm to produce a train of periodic optical pulses with full width at half maximum (FWHM) of 270 fs, repetition frequency of 20 MHz, and average output optical power of 146 W. The resulting femtosecond optical pulses are then amplified by using three kinds of Er3+-doped optical fibers with different lengths and Er3+-doped concentrations, respectively, while employing the same pumping laser. In the experiments, both the FWHM of amplified optical pulses and the amplifier gain are measured under different conditions. The optimization of optical pulse width is also carried out in terms of pumping light power.