Abstract: A laser oscillation amplifier includes a seed laser that can produce an input laser beam, a pumping source that can produce a pump light, a semiconductor laser shaping device that can receive the pump light and to produce a shaped pump light, a beam combiner that can combine the shaped pump light and the input laser beam, and a gain fiber coupled with the beam combiner. The gain fiber can absorb the pump light and amplifying the input laser beam to produce an output laser beam.

Abstract: An optical isolator includes a birefringent material and a Faraday rotator. The birefringent material receives a forward light propagating in a forward direction and a backward light propagating opposite to the forward direction. The birefringent material has an optical axis, wherein the forward light has a first polarization aligned perpendicular to the optical axis and is configured to pass the first birefringent material substantially along the forward direction. At least a portion of the backward light has a second polarization not perpendicular to the optical axis. The first birefringent material can displace the backward light to form a first displaced backward light. A Faraday rotator can rotate the forward light, and the backward light or the first displaced backward light by a same predetermined angle along the rotation direction.

Abstract: An optical isolator includes a birefringent material and a Faraday rotator. The birefringent material receives a forward light propagating in a forward direction and a backward light propagating opposite to the forward direction. The birefringent material has an optical axis, wherein the forward light has a first polarization aligned perpendicular to the optical axis and is configured to pass the first birefringent material substantially along the forward direction. At least a portion of the backward light has a second polarization not perpendicular to the optical axis. The first birefringent material can displace the backward light to form a first displaced backward light. A Faraday rotator can rotate the forward light, and the backward light or the first displaced backward light by a same predetermined angle along the rotation direction.

Abstract: An intra-cavity frequency-doubling laser device includes a first mirror and a second mirror defining a resonance cavity therein, a gain media to produce a first lasing light in response to an excitation energy received from outside of the resonance cavity, a non-linear optical material to generate a second lasing light in response to the first lasing light. The second lasing light and the first lasing light have different frequencies. The first mirror is reflective to the first lasing light and the second lasing light. The second mirror is reflective to the first lasing light and at least partially transmissive to the second lasing light. A birefringent optical material in the resonance cavity can rotate the polarization direction of at least one of the first lasing light and the second lasing light. An optical axis of the birefringent optical material and an optical axis of the non-linear optical material have an angle between 30 and 60 degrees.

Abstract: The invention relates to wavelength division multiplexing (WDM) and demultiplexing of optical signals using optical filters in free space. To minimize dispersion, the present invention uses relatively small angles of incidence. To avoid the need for a large package, the present invention utilizes reflective prisms to steer the reflected beams to provide a lateral shift in the beam path that ensures that the necessary space is provided between the input/output ports. Devices including a single adjustable filter are disclosed, along with devices having a plurality of filters.

Abstract: The present invention relates to an optical interferometer based on a Mach-Zehnder interferometer that can be used as an optical channel interleaver in wavelength division multiplexed (WDM) and dense wavelength division multiplexed (DWDM) optical networks. Optical channel interleavers/de-interleavers combine sets of WDM and DWDM channels for transmission over a network and/or separate WDM and DWDM signals into sets of channels with more convenient channel spacing for further de-multiplexing. The interferometer according to the present invention utilizes a ring resonator in each arm thereof as a phase shifter to provide a flat-top wavelength response with wide pass-bands and stop-bands.

Abstract: The invention provides a simple temperature insensitive optical retarder (waveplate) having a first and a second wedge shaped birefringent crystals, and a crystal mount comprising a first material having a low thermal expansion coefficient and a second material having a high thermal expansion coefficient, wherein the first and the second wedge shaped birefringent crystals are attached onto the first and second materials, respectively, so that the total retardance by the first and second birefringent crystals at a first temperature is substantially the same as that at a second different temperature at a given wavelength. Advantageously, the temperature insensitive optical retarder is simple, easy to construct, can be used for any birefringent crystal and does not require the use of different birefringent crystals.

Abstract: The invention relates to a micro-optic adhesive assembly and a method for making a micro-optic assembly. The method of joining optical assemblies in accordance with the present invention improves the strength and shock resistance of adhesive joints in micro-optic devices without affecting the optical path. The adhesive assembly of the present invention has sufficiently flexibility to be able to conform to different alignment geometries without introducing significant bulk or thermal expansion incompatibility. Further the improved method is compatible with the device manufacturing techniques and does not add significant manufacturing complexity.

Abstract: The present invention relates to an optical interferometer based on a Mach-Zehnder interferometer that can be used as an optical channel interleaver in wavelength division multiplexed (WDM) and dense wavelength division multiplexed (DWDM) optical networks. Optical channel interleavers/de-interleavers combine sets of WDM and DWDM channels for transmission over a network and/or separate WDM and DWDM signals into sets of channels with more convenient channel spacing for further de-multiplexing. The interferometer according to the present invention utilizes a ring resonator in each arm thereof as a phase shifter to provide a flat-top wavelength response with wide pass-bands and stop-bands.

Abstract: The invention provides a simple temperature insensitive optical retarder (waveplate) having a first and a second wedge shaped birefringent crystals, and a crystal mount comprising a first material having a low thermal expansion coefficient and a second material having a high thermal expansion coefficient, wherein the first and the second wedge shaped birefrigent crystals are attached onto the first and second materials, respectively, so that the total retardance by the first and second birefringent crystals at a first temperature is substantially the same as that at a second different temperature at a given wavelength. Advantageously, the temperature insensitive optical retarder is simple, easy to construct, can be used for any birefringent crystal and does not require the use of different birefringent crystals.

Abstract: The invention provides a transceiver including a ball lens, an optical filter disposed within the ball lens for transmitting a first optical signal at a first wavelength and for reflecting a second optical signal at a second wavelength, a light source for emitting the first optical signal to the ball lens, a receiver for receiving the second optical signal from the ball lens, and an input/output port optically coupled with the ball lens for at least one of receiving the first optical signal from the ball lens and transmitting the second optical signal to the ball lens. The ball lens comprises two half ball lenses and the optical filter is disposed at a mid-plane junction between the two half ball lenses.

Abstract: A fiber optical circulator in which is a light beam is fed from a fiber of a first port in a dual core glass capillary, then collimated before being passed to a birefringent crystal wherein the light beam is divided into two orthogonal components o and e with a displacement. The State of Polarization (SOP) of components then are changed into the same, perpendicular to the incident plane of the birefringent crystal prism by the group of Faraday Rotator and two Half-Wave Plates (HWP) that have different optical axis orientation and cover o and e components respectively. Then the light components with the same SOP pass into a birefringent prism where they receive angle correction to meet receiving requirement in incident angle for the fiber of port 2 without displacement due to their SOP. This is followed by a second group of HWP and Faraday Rotator that changes the SOP of two components back to orthogonal.

Abstract: A beam splitter and/or beam combiner is disclosed which in a splitting mode of operation receives an input beam of light and splits the beam into two orthogonally polarized parallel sub-beams of light. The device uses two wedges wherein at least one is birefringent or wherein both are birefringent such as a Wallaston prism, for splitting the input beam into two sub-beams wherein at least one diverges from the other, to provide two diverging beams. Only one or two small crystals are required to do this beam splitting. The two diverging beams are then made parallel by passing them through a prism, such as a roof prism, spaced from the beam splitting prism(s).

Abstract: The invention provides an optical collimator assembly having an optical fiber for transmitting a beam of light, a lens for substantially collimating a beam of light received from the optical fiber, and a light transmissive element disposed to receive a beam of light from the lens for correcting an angular deviation in the beam of light received from the lens. If desired, two wedges are used to correct an angular deviation of a beam exiting a collimator, wherein the two wedges have a relative rotational angle with respect to each other. The invention further provides a method for making an array of collimators having output beams substantially parallel to an axis of the collimator, or lens or lens system.

Abstract: Parallel optical beams emitted by an array of optical devices e.g. collimators are spaced by a distance that is not smaller than the diameter of the collimators etc. devices. To reduce the spacing of the beams at the point of incidence on the receiving element or device, a structure is provided having a first and a second array of reflective surfaces e.g. mirrors or prisms, the arrays defining pairs of corresponding reflective surfaces. The surfaces are arranged such that the beams reflected from the second array have a reduced spacing compared to the initial distance.

Abstract: The invention relates to wavelength division multiplexing (WDM) and demultiplexing of optical signals using optical filters in free space. To minimize dispersion, the present invention uses relatively small angles of incidence. To avoid the need for a large package, the present invention utilizes reflective prisms to steer the reflected beams to provide a lateral shift in the beam path that ensures that the necessary space is provided between the input/output ports. Devices including a single adjustable filter are disclosed, along with devices having a plurality of filters.

Abstract: The invention relates to the design of laser collimators for free space through-the-air optical links. The laser collimator provides means for expanding the diameter of a light beam emitted from the end of a monomode optical fiber that has been optical coupled to a semiconductor laser diode and projecting through free space the expanded beam as a low divergence beam of substantially parallel rays. The laser collimators disclosed are compact, simple to make, and overcome many of the deleterious effects that result from the requirement that the air-glass surface terminating the end of the monomode fiber coupled to the semiconductor laser is not normal to the axis of the optical fiber. Means are also disclosed for increasing the divergence of the cone of light emitted from the tip of an optical fiber thereby enabling the construction of laser collimators with larger expansion ratios in a compact size.

Abstract: The invention relates to a micro-optic adhesive assembly and a method for making a micro-optic assembly. The method of joining optical assemblies in accordance with the present invention improves the strength and shock resistance of adhesive joints in micro-optic devices without affecting the optical path. The adhesive assembly of the present invention has sufficiently flexibility to be able to conform to different alignment geometries without introducing significant bulk or thermal expansion incompatibility. Further the improved method is compatible with the device manufacturing techniques and does not add significant manufacturing complexity.