Abstract: A synchronous, tunable multi-optical filter system including two or more tunable optical filters, a shared diffraction grating, and a shared rotatable optical component, for example, a reflection prism, a mirror, etc., is provided. The shared diffraction grating, disposed in optical paths of both the tunable optical filters, disperses each collimated beam received therefrom into constituent wavelengths. By rotating the shared rotatable optical component disposed at a distance from the shared diffraction grating, using a rotation mechanism, the shared rotatable optical component communicates output beams having target wavelengths selected from the constituent wavelengths, to output elements of the tunable optical filters operating in individually configurable communication modes, for example, transmission and reflection modes.

Abstract: A system and a method for disinfecting air from airborne pathogens, for example, viruses, bacteria, etc., in an airflow system, are provided. One or more first reflectors reflect a high power, ultraviolet laser beam (UVLB) from an ultraviolet laser(s) into one or more airflow channels of the airflow system. One or more second reflectors are attached to internal surfaces of the airflow channel(s), in a free space optical connection to the first reflector(s), for reflecting the UVLB and increasing contact, utilization, and interaction of the UVLB with the airflow in the airflow channel(s) for irradiating and disinfecting the air therein. Air supply components on a ceiling blow the disinfected air from an airflow channel into an enclosed space for inhalation by occupants in the enclosed space, while air exhaust components on a floor exhaust air exhaled by the occupants into an airflow channel, thereby precluding cross-contamination in the enclosed space.

Abstract: A device component assembly including an upper support plate (USP) of glass and a lower support plate (LSP) of metal affixed to the USP, and a manufacturing method are provided. The USP and the LSP include openings of different shapes and sizes. The LSP includes gaps cut in different directions for reducing thermal expansion and tension generated during a temperature shift. Device components including optical, mechanical, electric, electronic, and optoelectronic components are mutually optically aligned and mounted on the USP and/or the LSP based on component requirements. The device components are mounted on the LSP through the openings of the USP. The optical components are affixed to the support plate(s) using a fastening material. One or more heat transfer members are affixed to the LSP for mounting the device component(s) thereon, after mutual optical alignment therebetween. The device component assembly is integrated in an optical or optoelectronic module or system.

Abstract: A tunable filter structure comprising of a rotating disk made of metal parts in which N diffractive elements like bulk gratings are adjusted and mounted individually to disperse the incoming light and form a Littman-Metcalf configuration for selecting different wavelength of light, a servo motor to rotate the disk, a reflective element like mirror and a multi-branch configuration comprising of M branches that are synchronized in time and are combined by an optical coupler or an optical switch. In the second embodiment, the diffractive elements are replaced by the reflective elements to form a Littrow configuration. The tunable filter can be used in combination of a gain medium like semiconductor optical amplifier (SOA) or an Erbium-doped fiber amplifier (EDFA), in a ring or linear configuration to make a sweeping light source with low cost and high sweeping frequency.

Abstract: A semiconductor laser chip is placed in between two Fiber Bragg gratings (FBGs), which are used as external cavities for the laser, to stabilize its center wavelength and to reduce its bandwidth. The first FBG is placed at the front facet of the laser chip, while the second FBG is placed on the back facet of the chip. The two FBGs are used to form an external cavity. Both FBGs can have same central wavelengths, different reflectivities and different bandwidths. The distance between the laser chip and the FBGs can varies from few millimeters to several meters. Since the FBGs have a very small wavelength drift with temperature fluctuations, the semiconductor laser has a stable center wavelength output. Another benefit of this setup is that the bandwidth of laser diode is also reduced.

Abstract: A new type of optical pressure sensor with adjustable sensitivity is proposed based on the fiber Bragg grating (FBG). In this technique, the pressure changes the length of a metal bellows which is placed behind a spring. The fiber grating is fixed over the bellows between a fixed position and the connection point of bellows and spring. The wavelength change of FBG is caused by the change in the bellows length; however, the spring controls the total length expansion of the bellows. It will bring two benefits: first it is easy to change the pressure sensing range by changing the spring rate; and secondly the spring improves the linearity of the wavelength sift due to the pressure. The FBG is installed outside of the bellows and is not in contact with the material in which the pressure should be measured (gas or liquid) in contrast with other pressure sensors where the FBG is inside the bellows.

Abstract: A new type of tunable fiber Bragg grating (FBG) is proposed based on the compression of FBG from both sides. In this technique, the FBG is compressed from both sides simultaneously which provides the more uniform force distribution along the grating compared to the compression from one side. As a result, the grating period changes uniformly due to compression and the same spectral shape can be achieved over a wide spectrum. The double-sided compression technique represents a significant improvement over the prior wavelength tunable fiber grating techniques, especially for the long gratings.

Abstract: A cell phone having not only radio frequency (RF) emitter and RF receiver but also having light emitter and light receiver works together with an earphone having not only speaker and microphone but also having light emitter and light receiver. User will talk or listen with the earphone and cell phone will connect the system to the wireless communication network using RF signal. Communication between cell phone and earphone is carried out using light-wave in free space. By using light-wave based earphone to communicate with cell phone; users becomes less exposed to RF radiations.

Abstract: A Fiber Bragg grating is sliced into small segments (such as 1 mm in length), the sliced fiber Bragg grating segments are used as external cavities for lasers to stabilize their center wavelength. In one embodiment, a semiconductor laser has an anti-reflection coating on the front facet and a high reflectivity coating on the back facet, a sliced fiber Bragg grating is used as a partial reflection mirror to form a lasing cavity. Since the sliced fiber Bragg grating has a very small wavelength drift with temperature change, the semiconductor laser has a stable center wavelength output. In the other embodiment, a solid state laser has an anti-reflection coating on the front facet and a high reflectivity coating on the back facet, a sliced fiber Bragg grating is used as a partial reflection mirror to form a lasing cavity. The solid state laser has a stable center wavelength output.

Abstract: A Fiber Bragg grating is sliced into small segments (such as 1 mm in length), the sliced fiber Bragg grating segments are used as external cavities for lasers to stabilize their center wavelength. In one embodiment, a semiconductor laser has an anti-reflection coating on the front facet and a high reflectivity coating on the back facet, a sliced fiber Bragg grating is used as a partial reflection mirror to form a lasing cavity. Since the sliced fiber Bragg grating has a very small wavelength drift with temperature change, the semiconductor laser has a stable center wavelength output. In the other embodiment, a solid state laser has an anti-reflection coating on the front facet and a high reflectivity coating on the back facet, a sliced fiber Bragg grating is used as a partial reflection mirror to form a lasing cavity. The solid state laser has a stable center wavelength output.

Abstract: Single longitudinal mode solid-state laser comprises solid-state laser and single-mode optical fiber, which Bragg grating is written on, as an external cavity. In one embodiment, the multimode laser is coupled from solid-state laser by lens system into external cavity which includes the optical fiber with Bragg grating written on. In the other embodiment, the multimode laser is coupled from solid-state laser directly into the external cavity which includes lensed optical fiber with Bragg grating written on. The Bragg grating selects lasing wavelength and discriminates against lasing of the other longitudinal modes in the multimode gain region. The solid-state laser with fiber Bragg grating external cavity generates single longitudinal mode laser with narrow spectrum and high side mode suppression ratio. The method is very simple and cost-effective.

Abstract: An invention proposes a new solution for the optical fiber gratings temperature compensation package that has an elongated body made out of a low coefficient of thermal expansion (CTE) material with a longitudinal internal passage therethrough and that transversely extends to a perimeter of the body all along between its first and second extremities and forms a longitudinal exterior opening. The latter allows the optical fiber to be transversely inserted therethrough and to be fixed in a stretched configuration to a first and second end pieces made out of a high CTE material and longitudinally slidably mounted on a respective of first and second extremities of the body.

Abstract: A tunable optical fiber grating device for tuning optical characteristic responses of an optical grating area of an optical fiber includes an elongated beam member defining a neutral plane with a first and a second ends and adapted to receive the fiber therealong. A securing member continuously secures the grating area all along the beam member between its ends and generally parallel to the neutral plane to allow for transmission of a bend of the beam member about the neutral plane to the grating area. A fixed support member has a screw for releasably securing the first end of the beam member within the neutral plane, and a mobile support member has a slotted element to slidably receive the second end of the beam member within the neutral plane.