Abstract: A compressive force is applied to a conventional air-spaced etalon filter to fine tune the thickness of the spacers to a precise and uniform optical length. The etalon is coupled to a housing device capable of adjusting the thickness of each spacer, thereby tuning the etalon to the desired filter wavelength. The resulting assembly is permanently set to the desired parameters for direct use in optical applications.

Abstract: Methods for forming optical systems are provided. A representative method includes the steps of: providing a substrate; depositing on the substrate a first contoured channel preform of material capable of ion exchange with the substrate; and diffusing ions from the first channel preform into the substrate to form a first waveguide channel at least partially buried in the substrate. Optical systems and other methods also are provided.

Abstract: Methods for forming optical systems are provided. A representative method includes the steps of: providing a substrate; depositing on the substrate a first contoured channel preform of material capable of ion exchange with the substrate; and diffusing ions from the first channel preform into the substrate to form a first waveguide channel at least partially buried in the substrate. Optical systems and other methods also are provided.

Abstract: A tunable optical source comprises a laser diode 105 and an external optical feedback device 135. The feedback device 135 has a waveguiding portion fabricated at least in part out of a glass material having both organic and inorganic components. Control means is provided for controlling the refractive index of the glass material so as to change the wavelength of feedback to the laser diode. The glass material may for example have thermo-optic properties and the control means might then be a heating device for heating the glass material. The feedback device 135 can have more than one portion, a second portion for example having controllable coupling characteristics for coupling optical radiation into or out of the feedback device 135. It also preferably has a portion for controlling optical path length in the feedback device 135.

Abstract: An optical characterisation device has a guiding body 200 and a diffractive structure 220 integrated with it. The guiding body 200 delivers radiation to the diffractive structure 220 at a preselected angle and the diffractive structure 220 diffracts at least a portion of radiation guided to it to give spatial resolution according to wavelength. A position sensitive detector 235 detects the position of the spatially resolved radiation and thus the radiation can be characterised according to wavelength. Embodiments of the present invention can be used to monitor and adjust the wavelength of a radiation source, using a feedback connection 135. By using the integrated approach, a very small structure can be realised and the structure can be relatively simply fabricated and assembled. The guiding body 200 might be either capable of supporting multimode propagation of the radiation or might be a single mode waveguide.

Abstract: In a tunable optical source, a diffraction device 115 is used to provide wavelength selective feedback to a laser diode 100. The diffraction device 115 is at least partially fabricated in a material whose refractive index is controllable so as to control the diffraction performance of the device. This allows the diffraction device 115 to be used in tuning the optical source, potentially without using moving parts. For instance, the refractive index can be controlled using a temperature change across material of the device 115. The diffraction device 115 can be mounted in free space in an external cavity with respect to the laser diode 100. Novel forms of diffraction device 115 are described. Tunable optical sources of this type can be used for instance in communications, particularly wavelength division multiplexing.

Abstract: In a tunable optical source, a zone plate device 100 is used to provide frequency selective feedback to a laser diode 110. The zone plate device 100 is positioned to receive an output mode of the laser diode 110 and to return a frequency selected image of the mode spot to the laser diode 110. By changing the refractive index of material of the zone plate device 100, it is possible to change the frequency providing the image at the point of return to the laser diode 110. This allows the zone plate device 100 to be used in tuning the optical source, without using moving parts. In an embodiment, the zone plate device 100 is at least partially fabricated in an electro-optic material such as SBN:75 and can therefore be tuned by using electrodes to apply an elecric field across it. The zone plate device 100 can be coupled directly to the laser diode 110 or via a waveguide section 105 which can be used to increase the output mode spot size from the laser diode 110 for delivery to the zone plate device 100.

Abstract: An integrated-optic device comprising a photorefractive substrate, an optical waveguide channel and at least one diffractive Bragg grating integrated in the substrate and intersecting the optical waveguide channel. The diffractive Bragg grating(s) causes at least a fraction of light coupled into the optical waveguide channel to be coupled out of the optical waveguide channel.

Abstract: An integrated-optic attenuator/equalizer device comprising a photorefractive substrate, at least one optical waveguide channel formed in the substrate, at least one diffractive-Bragg grating formed in the substrate, and a diffractive-Bragg grating modulator that is capable of modulating the diffractive Bragg grating(s). The diffractive-Bragg grating(s) intersects the optical waveguide channel. When a diffractive-Bragg grating formed in the substrate is modulated, at least a fraction of light of a wavelength associated with the modulated diffractive-Bragg grating is re-directed by the modulated diffractive-Bragg grating, thereby preventing the re-directed fraction of light from arriving at the output of the optical waveguide channel.

Abstract: An integrated-optic device comprising a photorefractive substrate, an optical waveguide channel and at least one diffractive Bragg grating integrated in the substrate and intersecting the optical waveguide channel. The diffractive Bragg grating(s) causes at least a fraction of light coupled into the optical waveguide channel to be coupled out of the optical waveguide channel.

Abstract: An integrated-optic device comprising a photorefractive substrate, at least one optical waveguide channel formed in the substrate, and at least one diffractive-Bragg grating formed in the substrate. The diffractive-Bragg grating(s) intersects the optical waveguide channel. The diffractive-Bragg grating(s) is configurable to cause at least a fraction of light of at least one wavelength that has been coupled into an input of the optical waveguide channel to be re-directed by the diffractive-Bragg grating(s), thereby preventing the re-directed fraction of light from arriving at the output of the optical waveguide channel.

Abstract: Methods for forming optical systems are provided. A representative method includes the steps of: providing a substrate; depositing on the substrate a first contoured channel preform of material capable of ion exchange with the substrate; and diffusing ions from the first channel preform into the substrate to form a first waveguide channel at least partially buried in the substrate. Optical systems and other methods also are provided.

Abstract: The invention relates to a wavelength-tunable laser configuration. The interspace between a laser source (200) and a control element (202), forming an external cavity, is short and has a length of preferably at most a few hundreds of wavelengths of the laser source (200). Also, the control element (202) is electrically tunable, which means that the control element (202) changes the optical properties of the external cavity with a movement of at least one tuning part (206, 402).