共查询到20条相似文献,搜索用时 15 毫秒
1.
V. M. Gelikonov G. V. Gelikonov V. V. Ivanov M. A. Novikov 《Technical Physics Letters》1999,25(5):405-407
It is shown that a polarization ring interferometer containing a Faraday cell can be used to compensate the reciprocal anisotropy
in round-trip optical circuits. It is established theoretically and experimentally that, unlike the case of conventional Faraday
mirrors, the quality of the restoration of the polarization in a compensator based on a polarization ring interferometer is
practically independent of the Faraday rotation angle. A deviation of the Faraday rotation angle from 45° leads only to an
additional power loss. The novel compensators can be used in fiber-optic circuits with a wideband light source or with several
sources having different wavelengths.
Pis’ma Zh. Tekh. Fiz. 25, 57–63 (May 26, 1999) 相似文献
2.
It is demonstrated theoretically and experimentally that linear velocities of reflecting objects may be measured using a resonant
ring interferometer with a low-frequency light source. The limiting sensitivity of this interferometer is estimated. It is
shown that a resonant ring interferometer can be used to measure extremely low linear velocities corresponding to subhertz
Doppler frequency shifts of light, which cannot be measured by conventional Doppler techniques based on direct measurements
of the frequency difference between the initial and reflected waves.
Pis’ma Zh. Tekh. Fiz. 25, 34–42 (December 12, 1999) 相似文献
3.
G. B. Malykin 《Technical Physics Letters》1999,25(8):668-669
A new method is proposed to eliminate the zero shift of a fiber ring interferometer induced by polarization nonreciprocity.
This method is based on periodic modulation of the polarization state of nonmonochromatic radiation at the entrance to the
interferometer ring system. Numerical estimates are given.
Pis’ma Zh. Tekh. Fiz. 25, 78–82 (August 26, 1999) 相似文献
4.
Petr Hlubina 《Journal of Modern Optics》2013,60(11):1595-1604
Abstract It is demonstrated experimentally that even if the spectral interference between two modes of an optical fibre excited by a low-coherence source is not resolved at its output by a spectrometer of a given resolving power, it is resolved in the Michelson interferometer configuration. In a tandem configuration of a dispersive Michelson interferometer and a two-mode optical fibre, the optical path difference (OPD) in the interferometer is adjusted close to the group OPD between modes to produce a low-frequency spectral modulation that can be processed. Thus, using the Fourier-transform method in processing the measured spectral modulations and subtracting the effect of the dispersive Michelson interferometer, the wavelength dependence of the group OPD between two modes of the optical fibre over a limited spectral region is obtained. 相似文献
5.
A new method of measuring the phase nonreciprocity in a passive ring resonator using a light source of low coherence is described.
The method provides effective suppression of noise from the backscattering of light in the ring resonator and insensitivity
of the interferometer to excursions of the resonance frequencies of the resonator due to reciprocal effects (e.g., thermal
expansion) and also permits modulation and compensation of the phase nonreciprocity by using a device outside the resonator
to shift the frequency of the light. One version of a low-coherent resonance ring interferometer is examined, viz., a two-transit
asymmetric interferometer with a rotating mirror.
Pis’ma Zh. Tekh. Fiz. 24, 24–29 (September 12, 1998) 相似文献
6.
É. I. Alekseev E. N. Bazarov Yu. A. Barannikov V. P. Gapontsev V. P. Gubin I. É. Samartsev N. I. Starostin 《Technical Physics Letters》1997,23(12):899-901
A study is made of the noise in the output intensity of a high-power superfluorescent fiber radiation source generating 20
mW in the 1.55 μm region of the spectrum. The source is constructed in an all-fiber technology from a quartz fiber activated with ytterbium
and erbium. It is found that the spectral density of the noise in the frequency range 100–500 kHz is uniform and corresponds
to the excess noise of “thermal” sources. It is shown that the noise in the output intensity of the source can be compensated
(decreased by an order of magnitude) in a two-channel scheme of photodetection, where it approaches a level close to the photon
shot noise.
Pis’ma Zh. Tekh. Fiz. 23, 1–6 (December 12, 1997) 相似文献
7.
Petr Hlubina 《Journal of Modern Optics》2013,60(4):537-547
Abstract The effect of a fibre-optic spectrometer on analysed spectral interference of two beams from a white-light source is studied theoretically and experimentally, including the effect of dispersion in an interferometer. First, the spectral interference law is expressed analytically under the condition of a Gaussian response function of a fibre-optic spectrometer, and then second, the theoretical analysis is accompanied by three experiments employing a fibre-optic spectrometer and a Michelson interferometer with different amounts of dispersion. Within one experiment the interference fringes are resolved over a wide spectral range and within two experiments the interference fringes are resolved only in a narrow spectral range around a wavelength at which the group optical path difference between interfering beams is zero. Knowing dispersion in the interferometer and the bandpass of the spectrometer, the positions of the interferometer mirror in the corresponding range are determined and good agreement between the recorded spectral interferograms and the theoretical ones is found. 相似文献
8.
This paper describes a new optoelectronic device—an optical transistor that provides power amplification of output visible
radiation. The optical transistor is structurally based on a metallized semiconductor plate with a microchannel gap in the
form of a planar Mach-Zehnder interferometer. A device of the light-light type is controlled by modulating the refractive
index in one arm of the interferometer.
Pis’ma Zh. Tekh. Fiz. 24, 17–21 (January 26, 1998) 相似文献
9.
É. I. Alekseev E. N. Bazarov V. P. Gubin V. G. Kovalenko A. I. Sazonov N. I. Starostin 《Technical Physics Letters》2002,28(11):949-951
A new optical scheme of the recirculation fiber loop interferometer with a Faraday reflector and a broadband radiation source is suggested. It is experimentally established that this scheme provides for a more than tenfold decrease in the instrument zero response caused by a spurious polarization modulation in the phase modulator. Factors leading to additional shifts in the instrument zero response are revealed. 相似文献
10.
An analysis is made of the transformation of the angular momentum density in the field of an unstable IV vortex of a few-mode
optical fiber. It is shown that the effect of mode dispersion of IV vortices is observed as the conversion of the polarization
and orbital components of the electrodynamic angular momentum. The angular momentum defect may be recorded experimentally
as a mechanical twist of the optical few-mode fiber. Formally the dispersion process resembles the conversion of the signs
of the orbital and polarization components of the angular momentum density. A complex pseudopotential, whose real and imaginary
parts characterize the field lines and lines of equal pseudopotential, is introduced to describe the energy flux density of
the fiber vortex. The conversion of field states with equivalent partial ê +
F
1(R)exp{−iφ} and ê2−
F
1(R)exp{+iφ} vortices was investigated experimentally.
Pis#x2019;ma Zh. Tekh. Fiz. 23, 58–65 (November 26, 1997) 相似文献
11.
Petr Hlubina 《Journal of Modern Optics》2013,60(5):791-799
Abstract The intermodal interference is analysed theoretically at the output of both a few-mode optical fibre alone and a tandem configuration of a Michelson interferometer with an optical fibre when higher-order intermodal dispersion effects are taken into account. It is revealed theoretically that in a special case of a two-mode optical fibre with a quadratic spectral dependence of the difference of propagation constants, which includes the equalization frequency with zero intermodal group delay, and fibre excitation by a broad-band light source, the time-domain visibility functions differ substantially from those corresponding to fibre excitation by a low-coherence light source. Moreover, measuring a two-mode optical fibre using time-domain and spectral-domain white-light interferometric techniques, some theoretical results are confirmed experimentally. 相似文献
12.
The physical mechanisms responsible for the formation of an optical vortex in the field of a few-mode fiber have been investigated
experimentally and theoretically. In an optical fiber with a parabolic refractive index profile an optical vortex is formed
as a result of interaction between circularly polarized rotating pure edge dislocations of circularly polarized even and odd
CP11 modes. In a stepped-index fiber the formation of an optical vortex is also related to the simultaneous propagation of even
and odd modes. The fields of these modes alter their structure over the fiber length and are not manifested by rotating edge
dislocations. It has been found experimentally that a stable vortex does not alter its degree of polarization of the field
at fiber lengths greater than 10 m. An unstable vortex, for which the product of the spin and the topological charge is always
less than zero, periodically decays and recovers at a beat length of 0.65 m. It is noted that a stable optical vortex cannot
be formed by orthogonally polarized LP11 modes. This is because an optical vortex transfers additional angular momentum like the CP11 modes whereas the LP11 modes do not transfer additional angular momentum of the field.
Pis’ma Zh. Tekh. Fiz. 23, 70–75 (March 12, 1997) 相似文献
13.
Abstract In this paper we study multiple interference produced by an interferometer when illuminated by an extended quasimonochromatic source. We define a relative modulation factor, which arises from grouping the interference terms for the same frequency. This relative modulation factor measures the departure from ideal behaviour of the interferometer. We also show that for some cases it is possible to associate a single aberrated optical system to each frequency, just as can be done for the single interference case, as was shown in a previous work; this allows an extension of the formalism presented therein. As an example, we calculate, for the case of a double-grating interferometer, the tolerance for the spatial extension of the source, where the modulation factor is close to unity. 相似文献
14.
O. I. Kotov L. B. Liokumovich V. M. Nikolaev V. Yu. Petrun’kin Zekhraui Buabid 《Technical Physics Letters》1997,23(5):380-382
A new method of detecting phase modulation, based on using an “external” optical waveguide interferometer, is considered.
This “detection” is weakly dependent on the length, position, and external conditions of the propagation channel for the phase-modulated
light and, in many cases may prove more efficient than conventional methods of constructing phasemodulated fiber-optic systems.
Pis’ma Zh. Tekh. Fiz. 23, 9–16 (May 26, 1997) 相似文献
15.
A. Ya. Vul’ S. V. Kidalov V. M. Milenin N. A. Timofeev M. A. Khodorkovski 《Technical Physics Letters》1999,25(4):321-323
A glow discharge in a mixture of argon and hydroxyl (OH) is investigated experimentally. It is shown that under certain discharge
conditions a considerable portion of the electrical energy imparted to the discharge is used to generate resonant emission
of OH molecules. The results obtained point to a realistic possibility of creating a new, ecologically friendly source of
optical radiation, which can replace mercury lamps in the near future.
“Applied Chemistry” State Scientific Center
Pis’ma Zh. Tekh. Fiz. 25, 62–66 (April 26, 1999) 相似文献
16.
Xiao Liang Yang Li Zhibo Liu Huai Wei Shuisheng Jian 《Journal of Modern Optics》2013,60(13):1254-1259
AbstractAn in-fiber liquid-level probe fabricated from homemade dual-mode elliptical multilayer-core fiber (EMCF) was proposed and experimentally demonstrated. The proposed sensor simply consists of a segment of the EMCF with one end coated with silver film, and a Michelson interferometer is roughly established when light from single-mode fiber incident from the other end. The detected interference patterns, rather clean due to the few-mode property, shift as the liquid level due to strong interaction between high-order modes and measurands through evanescent waves. Both the propagation characteristics and operation principle of such a sensor were demonstrated in detail, and sensitivities of 33.48, 43.35, and 48.93 pm/mm corresponding to liquid indices of 1.333, 1.353, and 1.373 were successfully achieved with a 50-mm EMCF probe, respectively. Moreover, the proposed sensor had the potential to discriminate measurand index after proper calibration. 相似文献
17.
Liren Liu 《Journal of Modern Optics》2013,60(10):1605-1618
Abstract Based on the partially coherent effect that lies between the Talbot effect and the Lau effect, a novel type of interferometry is proposed in this paper for a general configuration. The resultant interferogram is characterized by two different grating-like carriers. Such an interferometer becomes a Talbot or a Lau interferometer by adjusting the source slit to one or other of the two extremes of coherence. The partially coherent effect and the performance of the interferometer are analysed in detail in terms of the ambiguity function. Experimental results are shown to be in good agreement with the predicted intensity distributions. 相似文献
18.
An intermodal fiber interferometer in a bidirectional continuous excitation regime with an increasing number of modes propagating along the lightguide is analyzed. The potential to determine the point of fiber perturbation regardless of the conditions of impact is demonstrated experimentally. 相似文献
19.
A. V. Volyar V. Z. Zhilaitis T. A. Fadeeva V. G. Shvedov 《Technical Physics Letters》1999,25(3):185-186
It is shown that the symmetry properties of the locally isotropic inhomogeneous medium of an optical fiber cause circular
and linear topological birefringence. The circular birefringence δn
C
in graded-index fibers is ∼(λ/ρ)2 (where λ is the wavelength and ρ is the core radius), while the linear birefringence is δn
L
∼(λ/ρ)3. This topological birefringence is characterized not only by the polarization basis (as in crystals for example) but also
by the magnitude and sign of the topological charge of the guided vortex. This topological birefringence forms the basis of
the instability of the fiber IV vortex and is observed experimentally as the combined Rytov-Magnus effect.
Pis’ma Zh. Tekh. Fiz. 25, 41–46 (March 12, 1999) 相似文献
20.
Nonlinear Brownian motion in stochastic rachets is investigated by electronic simulation methods. It is shown experimentally
that it is possible to sort particles by mass using a discrete random process, binary noise, as the source of the nonequilibrium
stochastic ratchets.
Pis’ma Zh. Tekh. Fiz. 24, 47–53 (January 26, 1998) 相似文献