In this paper, by shortening the cavity length, we have realized all-fiber Tm-doped fiber laser with pulse width less than 600 fs based on nonlinear polarization rotation effect. Under the condition of pump power of 0.281 W, the traditional soliton limit pulse is realized by adjusting the polarization controllers. The pulse width is 560fs and consistent with the theoretical calculation of the limit pulse width 569fs, repetition frequency is 55.25 MHz, the central wavelength is 1978.34 nm and the 3dB spectral width is 7.25 nm. The traditional soliton index is helpful to improve the application of ultrafast Tm-doped fiber laser in mid-infrared light source and medical operation.
Proc. SPIE. 9300, International Symposium on Optoelectronic Technology and Application 2014: Infrared Technology and Applications
KEYWORDS: Gaussian beams, Polarization, Receivers, Turbulence, Transmittance, Atmospheric turbulence, Atmospheric propagation, Global system for mobile communications, Atmospheric optics, Beam controllers
Based on partially coherent polarized light transmission characteristics of the atmosphere, an intensity expression of
completely coherent flashing light is derived from Andrews scale modulation method. According to the generalized
Huygens-Fresnel principle and Rytov theory, the phase fluctuation structure function is obtained on condition that the
refractive index profile in the atmosphere meet Von Karman spectrum, then get the arrival Angle fluctuation variance.
Through the RMS beam width of gaussian beams in turbulent atmosphere, deviation angle formula of fully coherent
gaussian beams in turbulence atmosphere is attained, then get the RMS beam width of partially coherent and derivation
angle expression of GSM beam in turbulent atmosphere. Combined with transmission properties of radial polarized laser
beam, cross spectral density matrix of partially coherent radially polarized light can be gained by using generalized
huygens-fresnel principle. And light intensity and polarization after transmission can be known according to the unity of
coherence and polarization theory. On the basis of the analysis model and numerical simulation, the simulation results
show that: the light spot caused by atmospheric turbulence of partially coherent polarization will be superior to
completely polarized light.Taking advantage of this feature, designed a new wireless suppression technology of
atmospheric turbulence, that is the optimization criterion of initial degree of coherent light beam. The optimal initial
degree of coherent light beam will change along with the change of atmospheric turbulence conditions,make control the
beam’s initial degree of coherence to realize the initial degree of coherence of light beam in real time and dynamic
control. A spatial phase screen before emission aperture of fully coherent light is to generate the partially coherent light,
liquid crystal spatial light modulator is is a preferable way to realize the dynamic random phase. Finally look future of
the application research of partially coherent light.
The intelligent control of simulation target with infrared imaging target in the indoor and outdoor
environment can effectively and quantitatively evaluated the parameters such as the minimum resolution
temperature difference（MRTD）and spatial resolution of airborne forward looking infrared, infrared detection
and tracking, infrared alarm, and etc.
This paper focused on introducing the working principles of the intelligent control simulation target of
Infrared imaging target, studying the thermal radiation characteristics of the infrared target surface material,
analyzing the influences of the infrared radiation energy distribution, and developing the intelligent control
simulation target with IR imaging target for hardware-in-the-loop simulation test. The intelligent control
simulation target which area was 5 ㎡ and concluded 44 infrared targets including two kinds of infrared
targets ,0.25ｍ×0.25ｍ, and 0.25m×0.5m, achieved 1℃～10℃ temperature simulation of target and the
background, and temperature control precision better than 0.5℃. Field test requirements were achieved by
The Hardware-in-the-loop(HWIL) simulation test is one of the important parts for the development and performance
testing of semi-active laser-guided weapons. In order to obtain accurate results, the confidence level of the target
environment should be provided for a high-seeker during the HWIL simulation test of semi-active laser-guided weapons, and one of the important simulation parameters is the laser energy characteristic. In this paper, based on the semi-active laser-guided weapon guidance principles, an important parameter of simulation of confidence which affects energy characteristics in performance test of HWIL simulation was analyzed. According to the principle of receiving the same energy by using HWIL simulation and in practical application, HWIL energy characteristics simulation systems with the crystal absorption structure was designed. And on this basis, the problems of optimal design of the optical system were also analyzed. The measured results show that the dynamic attenuation range of the system energy is greater than 50dB, the dynamic attenuation stability is less than 5%, and the maximum energy changing rate driven by the servo motor is greater than 20dB/s.