National Research Council of Canada

Metrophotonics Inc.

Other

Emil S Koteles

Jian-Jun He

Michael Davies

Sylvain Charbonneau

Bryant P Hichwa

Philip J Poole

Orazio Berolo

John Wade

Boris Lamontagne

Lynden Erickson

Andre Delage

Andr&eacute; Del&acirc;ge

L Erickson

B Lamontagne

A Delage

Jian Jun He

Geofrey C Aers

Lynden E Erickson

A dynamic gain equalizer using amplification instead of attenuation is disclosed. The device relies on integrated semiconductor optical amplifiers in line with a demultiplexer on a single integrated substrate for performing equalization of signals within each of a plurality of channels.

Optical dynamic gain amplifier

A waveguide optical monitor is disclosed. The device has an optical input port coupled through a switch to a plurality of input waveguides. A dispersive element disperses light within the input optical waveguides toward a plurality of output waveguides. There are a plurality of photodetectors each optically coupled to an output waveguide. The photodectors are for sensing an intensity of light within the waveguide with which it is optically coupled. An optical switch in optical communication with the optical input port and for switching light received at the optical input port to one of the plurality of input waveguides. Also, an angular dispersive element is present for receiving light from any one of the waveguides and for dispersing the light toward a plurality of output waveguides in dependence upon the input waveguide position and a wavelength of the light such that light directed from the first of the plurality of input waveguides toward the plurality of output waveguides has a first centre wavelength within each of the output waveguides and light directed from the second of the plurality of input waveguides toward the plurality of output waveguides has a second different centre wavelength within each of the output waveguides, the second different center wavelength different form any first center wavelength.

Resolution enhanced optical spectrometer having a fixed number of photodetector elements

The present invention relates to a semiconductor optical amplifier system integrated within a semiconductor waveguide structure. The semiconductor optical amplifier system comprises a first semiconductor optical amplifier having a first spectral response and a second semiconductor optical amplifier having a second other spectral response. The second semiconductor optical amplifier is coupled to the first semiconductor optical amplifier for optically receiving an amplified optical signal from the first semiconductor optical amplifier. The center wavelengths of the first and the second spectral response are selected such that an optical signal provided to the first semiconductor optical amplifier and amplified thereby and then provided to the second semiconductor optical amplifier and amplified thereby is amplified approximately a same amount across a band of wavelengths larger than the band of wavelengths across which the optical signal was amplified approximately consistently by the first semiconductor optical amplifier alone.

Cascaded semiconductor optical amplifier

A waveguide optical monitor is disclosed. The device has an optical input port coupled through a switch to a plurality of input waveguides. A dispersive element disperses light within the input optical waveguides toward a plurality of output waveguides. There are a plurality of photodetectors each optically coupled to an output waveguide. The photodectors are for sensing an intensity of light within the waveguide with which it is optically coupled. An optical switch in optical communication with the optical input port and for switching light received at the optical input port to one of the plurality of input waveguides. Also, an angular dispersive element is present for receiving light from any one of the waveguides and for dispersing the light toward a plurality of output waveguides in dependence upon the input waveguide position and a wavelength of the light such that light directed from the first of the plurality of input waveguides toward the plurality of output waveguides has a first centre wavelength within each of the output waveguides and light directed from the second of the plurality of input waveguides toward the plurality of output waveguides has a second different centre wavelength within each of the output waveguides, the second different centre wavelength different form any first centre wavelength.

A homogeneous semiconductor waveguide structure having an undoped core layer and doped cladding layers on both sides of the core layer is proposed wherein the waveguide core is substantially thick providing polarization independence. Because of the cladding layers having low refractive index contrast with respect to the core and being on opposing sides resulting in a substantially symmetrical structure, the waveguide, can be made single-mode with low polarization sensitivity, thus improving characteristics for conducting light therein. Furthermore, the enlarged mode size increases coupling efficiency. Also, since the waveguide is grown from a single semiconductor composition lattice matched to the substrate, wafer uniformity and reproducibility are enhanced. The three layer structure reduces birefringence sufficiently that a yield enhancing etch stop layer can be added to the structure without substantially adverse effects.

Polarization independent waveguide structure

A planar waveguide optical device whose wavelengths are stabilized by temperature, has an input channel, a series of output data channels, and a dispersive element, such as a diffraction grating or phase array, for directing component wavelengths of incoming light into the respective output data channels. A pair of monitor channels have a separation less than, and a width greater than, the data channels. A differential feedback arrangement controls the temperature of the demultiplexer according a differential signal received from the pair of monitor channels.

Wavelength stabilized planar waveguide optical devices incorporating a dispersive element

A device for compensating the temperature sensitivity normally associated with an integrated optical waveguide grating device has a temperature compensating slab waveguide region. This compensating region is provided within the slab waveguide region normally present in the grating device by modifying a sub-region of a predetermined shape and dimension to change its temperature coefficient of refractive index. This method and device can be applied to reflective and transmissive diffraction gratings and to phased array waveguide gratings.

Athermal waveguide grating based device having a temperature compensator in the slab waveguide region

Bandgap tuning of semiconductor well structure

A device for compensating the birefringence normally associated with an integrated optical waveguide grating device has a polarization compensating slab waveguide region. This compensating region can be provided within the slab waveguide region normally present in the grating device by etching, doping, ion implanting a sub-region of a predetermined shape and dimension to change its birefringence. Alternatively, or in combination with changing the birefringence in this sub-region, electrodes can be provided for electro-optically changing the birefringence dynamically as required. This device can be applied to reflective and transmissive diffraction gratings and to phased array waveguide gratings.

Optical grating-based device having a slab waveguide polarization

An active semiconductor device that performs in a substantially polarization independent manner. A quantum well waveguide is intermixed by intermixing atoms across an interface between well and barrier layers. The atoms include at least 2 groups wherein intermixing of one group is at a substantially greater rate than another group. Cations are interdiffused at a greater rate than said anions across interfaces between well and barrier layers. The intermixing must be sufficient to provide strain within layers of the waveguide and sufficient to at least partially degenerate light hole and heavy hole bands of the structure. Preferably intermixing is sufficient to completely degenerate light hole and heavy hold bands to essentially produce a device that is completely polarization independent.

Fabrication of quantum well polarization independent active devices

A method of selectively tuning the bandedge of a semiconductor heterostructure includes repeatedly forming a disordered region that is spatially separated from a quantum well active region and subsequently annealing the heterostructure each time after the disordered region is formed, so that vacancies/defects in the disordered region diffuse into the quantum well region and enhance interdiffusion at the well-barrier heterojunctions. Repeating, the disordering followed by annealing allows for a greater range in bandgap tuning. The heterostuctures of interest are IH-V material systems, such as AlGaAs/GaAs, where the active region includes structures such as a single quantum well, a multiple quantum well, or a superlattice.

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Ottawa, Canada

Emil S Koteles