摘要:
Since the magnitude of a nonlinear effect depends on the nonlinearity coefficient of the microstructured fiber and the intensity of pump light, intensity of pump light is adjusted. The intensity of the pump light is adjusted by an optical amplifier, an optical attenuator, or a pre-emphasizing filter under the control of a control unit. The control unit controls the intensity of the pump light based on a look-up table which is prepared in advance by experiment or calculation, or based on a function of the pump and signal wavelength.
摘要:
In one embodiment of the present invention, a method includes introducing an optical signal into a first arm and a second arm of an optical device; self-phase modulating the optical signal propagating in the first arm; and outputting a high intensity portion of the optical signal spatially separated from a low intensity portion of the optical signal. In such manner, optical signals input into the optical device may be restored via cleaning and shaping.
摘要:
La présente invention concerne le domaine des antennes et a plus particulièrement pour objet une antenne comportant un générateur (1) d'un rayonnement laser (2) et des moyens de couplage (4) d'un signal électrique à ce rayonnement laser, cette antenne étant caractérisée en ce que le générateur (1) d'un rayonnement laser (2) est un laser femto-seconde.
摘要:
An entirely passive all-optical device, referred to as an optical hard limiter, consists of alternating layers of materials having oppositely signed Kerr coefficients and substantially different linear indices of refraction, wherein the higher linear index material has the negative Kerr coefficient and the lower linear index material has the positive Kerr coefficient. The optical device has two distinct transmittance curves. Various optical devices and systems can be built from such optical hard limiters.
摘要:
The present invention relates to novel optical devices operating in the infrared, based on indirect narrow-gap superlattices (INGS) as the active optical materials. The novel optical devices include (1) wideband all-optical switches, which combine small insertion loss at low light intensities with efficient optical switching and optical limiting at high efficiency and low tunneling noise currents, suitable for use in longwave infrared focal plane arrays. INGS comprise multiple semimetal (22) semiconductor (26) layers having compatible crystal symmetry across each heterojunction between a given semimetal (22) sandwiched between semiconductor layers (26). Each semiconductor layer (26) is thin enough that there is coupling between adjacent semiconductor layers (26). The present invention utilizes INGS, which are fabricated to meet the criteria Eindg
摘要:
A transient optical element is created by providing a body (11) of a third order non-linear material and then passing a pulse of light through the body of non-linear material. The pulse of light has a cross-sectional area corresponding to the cross-sectional area of the transient optical element to be created and power sufficient to induce an index of refraction change over the portion of the body of non-linear material through which it passes. The portion of the body of non-linear material having the induced index of refraction change constitutes the transient optical element with the duration of the transient optical element depending on the response time of the non-linear material and the duration of pulse of light. Typical optical elements that can be so created include prisms, lenses. gratings, mirrors, beamsplitters and wave guides. By forming a plurality of optical elements within the third order non-linear material rather than simply a single optical element, a transient optical circuit can be created.
摘要:
Le système optique décrit comprend au moins une première source (20) de rayonnement électromagnétique (rayonnement d'un faisceau de signaux), un dispositif (40) pour traiter le rayonnement d'un faisceau de signaux, et un détecteur (60) pour détecter le rayonnement du faisceau de signaux traité. Le dispositif de traitement fonctionne par exemple comme un modulateur d'amplitude, un démultiplexeur ou un commutateur et comprend une région de matières (42) présentant une réponse optique non linéaire à une ou plusieurs longueurs d'ondes résonantes de rayonnement électromagnétique, ainsi qu'au moins une seconde source (44) de rayonnement électromagnétique (rayonnement d'un faisceau de commande) pour induire sélectivement la réponse optique non linéaire. D'une manière significative, la longueur d'ondes, la durée et l'intensité du rayonnement du faisceau de commande sont choisies pour induire une réponse optique non linéaire résonante, essentiellement exempte de toute composante relativement lente, dans ladite région de matière à des vitesses de répétition supérieures à environ 2,5 x 104 Hz, ou supérieures à environ 3,3 x 1010 Hz, ou même aussi élevées ou plus élevées que 2,5 x 1011 Hz environ.
摘要:
A system is described. The system includes HNLF (206) for generating an optical frequency comb (212) and a single mode fiber (208) for reducing a pulse duration of comb. The system includes a FRM (210) to reflect the light in back propagation through the HNLF and the single mode fiber. Perturbations in a state of polarization caused by the HNLF and the single mode fiber are cancelled between the forward propagation and the backward propagation. The optical frequency comb may then be polarization maintaining without an active component such as a polarization controller and a feedback circuit.