共查询到20条相似文献,搜索用时 140 毫秒
1.
模拟仿真了谐振式光纤环腔的透射谱线以及鉴频曲线,得透射谱线最低谷值对应为调制谐振点,鉴频曲线的线性区为陀螺的工作范围区,线性区中点对应谐振点,可作为标度因数最大值.为了实现谐振点的高精度锁频和稳频,设计了谐振式光纤陀螺角速率测定方案,使用比例积分反馈电路实施锁频,利用正弦波扫描窄线宽激光器(线宽小于1kHz)的压电转化模块,使激光器谐振腔长发生变化,从而改变其输出频率,对谐振光纤环腔随外界环境变化同时进行跟踪和锁定.利用线宽法测试并计算出光纤环形谐振腔的品质因数值为107,对比分析了光纤环腔在谐振点和非谐振点锁定情况下的光电探测实时输出,并通过转动测试,得到两种情况下锁定后陀螺的连续转动效果.计算了光纤陀螺系统理论检测灵敏度,结果表明:谐振点锁定后转动效果对应的陀螺输出电平值为锁定非谐振点转速电平值的3倍,验证了谐振式光学陀螺谐振点锁频的重要性. 相似文献
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为提高光纤激光器无源自调整相干合成阵列的效率、稳定性和可扩展性,提出了基于公共光纤环形腔耦合与单模光纤滤波的光纤激光器相干合成方案。将多个2×2的光纤耦合器分别插入各单元激光器的谐振腔,利用耦合器余下的端口,两两相连构成公共环形耦合腔。采用单模光纤滤波技术,提高了各输出激光束之间相位锁定的稳定性。利用该方案在实验上实现了三路光纤激光器的被动锁相输出,实验测得的远场干涉光斑、输出功率及光谱均表明该方案适于构建性能较好的光纤激光器相干合成阵列。 相似文献
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基于KTP键合晶体采用Hansch-Couillaud频率锁定技术实现了双波长外腔同时共振,理论和实验上分别研究了基于键合KTP晶体的HC频率锁定方案. 研究表明,与采用单KTP晶体的结果相比,采用键合KTP晶体进行HC锁频时,能将激光频率分别锁定到e1光或e2光的共振峰值. 实验中将环形腔腔模频率锁定到938nm激光器的输出频率上,1583nm激光器的输出频率锁定到环形腔腔模频率上,从而实现了三者之间的相位关联锁定.
关键词:
键合KTP晶体
Hansch-Couillaud锁频
双波长外腔共振 相似文献
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激光输入光纤环形腔内相位调制输出功率谱分析 总被引:1,自引:0,他引:1
从理论上详细分析了光纤环形腔有内相位调制时的输出光电流功率谱密度函数,该理论对任意相干长度的输入激光光源都是有效的。理论结果和实验数据表明,过快的相位调制能够平坦光电流功率谱上由于环形腔谐振特性而形成的周期性小峰,而弱相位调制对环形腔输出功率谱则影响不大。 相似文献
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光纤环形外腔半导体激光器频偏特性研究 总被引:1,自引:1,他引:0
本文给出了在环形光纤外腔光反馈之下半导体激光器频偏特性的小信号分析理论.分析表明,尤其在千兆赫以下的调制频段中,耦合腔相移、内外腔光耦合强度及内外腔光场相位失谐对频偏功率比均有显著影响.可望用作强度调制直接检测高速率、长距离光纤通信系统中的光源. 相似文献
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噪声免疫腔增强光外差分子光谱技术(NICE-OHMS)由于结合了频率调制光谱与腔增强光谱两种技术,不仅可以将激光耦合到高精细度谐振腔大幅提高腔内功率,还可以实现低气压样品气体的高灵敏测量,因此基于该技术可以实现分子吸收线的饱和,获得亚多普勒光谱,从而能作为激光频率锁定的参考.本文基于光纤激光器的NICE-OHMS技术,将光纤激光器频率锁定到NH3的亚多普勒吸收线上.首先分析了基于Pound-Drever-Hall和DeVoe-Brewer技术实现激光到腔模和调制频率到腔自由光谱区频率锁定的性能,之后在腔内气压为70 mTorr条件下,测量了半高全宽为2.05 MHz的NH3亚多普勒信号,最后将1.53μm的光纤激光器频率锁定到该亚多普勒吸收线上,相对频率偏差为16.3 kHz,阿伦方差结果显示,136 s积分时间下频率稳定度达到1.6×10~(-12). 相似文献
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Judd-Oflet analysis of spectrum and laser performance of Ho:YAP crystal end-pumped by 1.91μm Tm:YLF laser 下载免费PDF全文
The Ho:YAP crystal is grown by the Czochralski technique.The room temperature polarized absorption spectra of Ho:YAP crystal was measured on a c cut sample with 1 at% holmium.According to the obtained Judd-Ofelt intensity parameters Ω2 = 1.42 × 10-20 cm2,Ω4 = 2.92 × 10-20 cm2,and Ω6 = 1.71 × 10-20 cm2,this paper calculated the fluorescence lifetime to be 6 ms for 5I7 →5 I8 transition,and the integrated emission cross section to be 2.24×10-18 cm2.It investigates the room temperature Ho:YAP laser end pumped by a 1.91 μm Tm:YLF laser.The maximum output power was 4.1 W when the incident 1.91 μm pump power was 14.4 W.The slope efficiency is 40.8%,corresponding to an optical to optical conversion efficiency of 28.4%.The Ho:YAP output wavelength was centred at 2118 nm with full width at half maximum of about 0.8 nm. 相似文献
12.
Effects of correlations between the real and imaginary parts of quantum noise on intensity fluctuation for a saturation laser model 下载免费PDF全文
This paper studies the effects of cross-correlations between the real and imaginary parts of quantum noise on the laser intensity in a saturation laser model. It derives the analytic expressions of the intensity correlation function C(τ) and the associated relaxation time T(C) in the case of a stable locked phase resulting from the cross-correlation λq between the real and imaginary parts of quantum noise. Based on numerical computations it finds that the presence of cross correlations between the real and imaginary parts of quantum noise slow down the decay of intensity fluctuation, i.e., it causes the increase of intensity fluctuation. 相似文献
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In this paper the generation of four-wave mixing (FWM) signal using a
noncycling transition of caesium atoms is investigated when the pumping laser
is locked to the transition $6{\rm S}_{1/2}F=4\to6{\rm P}_{3/2}F'=4$, and
meanwhile the probe frequency is scanned across the $6{\rm S}_{1/2}F=4
\to6{\rm P}_{3/2}$ transition. The efficiency of the four-wave mixing signal
as a function of the intensity of the pumping beams and the detuning of the
pumping beams is also studied. In order to increase the detection
efficiency, a repumping laser which is resonant with $6{\rm S}_{1/2}
F=3\to 6{\rm P}_{3/2}F'=4$ transition is used. A theoretical model is also
introduced, and the theoretical results are in qualitative agreement with
experimental ones. 相似文献
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Effects of correlations between the real and imaginary parts of quantum noise on intensity fluctuation for a saturation laser model 下载免费PDF全文
This paper studies the effects of cross-correlations between the
real and imaginary parts of quantum noise on the laser intensity in
a saturation laser model. It derives the analytic expressions of the
intensity correlation function ${C(\tau)}$ and the associated
relaxation time ${T({C})}$ in the case of a stable locked phase
resulting from the cross-correlation ${\lambda_q}$ between the real
and imaginary parts of quantum noise. Based on numerical
computations it finds that the presence of cross correlations
between the real and imaginary parts of quantum noise slow down the
decay of intensity fluctuation, i.e., it causes the increase of
intensity fluctuation. 相似文献
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Simulation of dielectric resonator for high-Tc radio frequency superconducting quantum interference device 下载免费PDF全文
Nowadays, the high-critical-temperature radio frequency
superconducting quantum interference device (high-$T_{\rm c }$ rf
SQUID) is usually coupled to a dielectric resonator that is a
standard $10\times 10\times 1$~mm3 SrTiO$3 (STO) substrate
with a YBa2Cu$3O$_{7 - \delta }$ (YBCO) thin-film flux
focuser deposited on it. Recently, we have simulated a dielectric
resonator for the high-$T_{\rm c }$ rf SQUID by using the ANSOFT High
Frequency Structure Simulator (ANSOFT HFSS). We simulate the
resonant frequency and the quality factor of our dielectric
resonator when it is unloaded or matches a 50-$\Omega$ impedance.
The simulation results are quite close to the practical
measurements. Our study shows that ANSOFT HFSS is quite suitable for
simulating the dielectric resonator used for the high-$Tc rf
SQUID. Therefore, we think the ANSOFT HFSS can be very helpful
for investigating the characteristics of dielectric resonators for
high-$Tc rf SQUIDs. 相似文献
17.
High power high beam quality diode-pumped 1319-nm Nd:YAG oscillator-amplifier laser system 下载免费PDF全文
This paper demonstrated a high power and high beam quality
diode-pumped 1319-nm Nd:YAG master oscillator-power amplifier laser
system. A thermally near-unstable resonator with four-rod
birefringence compensation flat--flat cavity was adopted as the
master oscillator. A solid etalon was inserted in the unidirectional
ring resonator to compress the laser linewidth. Under a repetition
rate of 500~Hz and pulse width of 160~\mus, the master oscillator
delivers an average output power of 16.8~W at 1319~nm with linear
polarisation, beam quality factor M^{2} = 1.16 and linewidth of
3.2~GHz. A double-pass power amplifier with two amplifier stages was
employed for higher power scaling and the output power was amplified
to be 25.9~W with M^{2} = 1.43. 相似文献
18.
Energy transfer probability in organic electrophosphorescence device with dopant 总被引:1,自引:0,他引:1 下载免费PDF全文
Based on the energy transfer process from host to dopant in an organic
electrophosphorescent (EP) device, the expression of energy transfer
probability ($\eta )$ between the host (TPD) and guest (Ir(ppy)$_{3})$ EP
systems was proposed. The results show that: ({1}) The rate of the triplet
energy transfer ($K_{\rm HG}$ and $K_{\rm GH})$ increases exponentially with
increasing donor-acceptor molecular distance ($R$), whereas decreases as the
intermolecular distance ($R_{\rm HH})$ increases from 0.8 to 2.4 nm.
Furthermore, $K_{\rm GH}$ changes more quickly than $K_{\rm HG.}$ ({2}) The energy
transfer probability ($\eta )$ increases as $R$ reduces, and the $R_{\rm HH}$
changes can be safely neglected for $R<$0.9 nm. The situation changes for
0.9nm$ < R < 1.1$nm, $R_{\rm HH }$ ($<1$nm) plays an essential role when
$\eta $ changes
and increases with the latter. However, if $R > 1.1$nm, the transfer
probability will be below zero. Here, the energy transfer principle may be
less important, and the high electroluminescence (EL) quantum efficiency of
phosphorescent system will be attributed to the direct electron-hole
recombination in phosphorescent molecules. ({3}) The $\eta $ will increase when the
Forster radius ($R_{0})$ increases or Gibb's energy decreases. 相似文献
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Electron tunnelling phase time and dwell time through an associated delta potential barrier 下载免费PDF全文
The electron tunnelling phase time τP and dwell time τD through an associated delta potential barrier U(x) = ξδ(x) are calculated and both are in the order of 10^-17~10^-16s. The results show that the dependence of the phase time on the delta barrier parameter ξ can be described by the characteristic length lc = h^2/meξ and the characteristic energy Ec=meξ^2/h^2 of the delta barrier, where me is the electron mass, lc and Ec are assumed to be the effective width and height of the delta barrier with lcEc=ξ, respectively. It is found that TD reaches its maximum and τD = τp as the energy of the tunnelling electron is equal to Ec/2, i.e. as lc =λDB, λDB is de Broglie wave length of the electron. 相似文献