Abstract: An acousto-optic (AO) device includes an AO crystal having a plurality of faces including a first face and a second face. An input transducer bonded to the first face (top electrode) for receiving a radio frequency (RF) signal and launching bulk acoustic waves (BAWs) configured to interact with an optical beam propagating in the AO crystal, wherein the BAWs are received at least in part by the second face after interacting with the optical beam. The second face has a roughened surface portion over an area of at least (?) 50% of an area of the top electrode, and a root mean square (rms) surface roughness?1 ?m and a surface profile derivable from a Fourier transform which provides at least one a first spatial frequency peak from 1 cycle/mm to 300 cycles/mm or at least one band of spatial frequency peaks from 1 cycle/mm to 300 cycles/mm.

Abstract: An acousto-optic (AO) device includes an AO crystal having a plurality of faces including a first face and a second face. An input transducer bonded to the first face (top electrode) for receiving a radio frequency (RF) signal and launching bulk acoustic waves (BAWs) configured to interact with an optical beam propagating in the AO crystal, wherein the BAWs are received at least in part by the second face after interacting with the optical beam. The second face has a roughened surface portion over an area of at least (?) 50% of an area of the top electrode, and a root mean square (rms) surface roughness ?1 ?m and a surface profile derivable from a Fourier transform which provides at least one a first spatial frequency peak from 1 cycle/mm to 300 cycles/mm or at least one band of spatial frequency peaks from 1 cycle/mm to 300 cycles/mm.

Abstract: A Fabry-Perot tunable filter (FPTF) includes a top mirror having a first surface for receiving light and a second surface opposite the first surface. A movable mirror having a front side is secured to the second surface of the top mirror and includes back side. The movable mirror includes an inner bend resistant portion, wherein the front side includes a flexible front side portion outside the inner bend resistant portion recessed relative to the inner bend resistant portion, and a front side outer bend resistant portion thicker than the flexible front side portion. The back side includes a flexible back side portion outside the inner bend resistant portion and a back side outer bend resistant portion thicker than the flexible back side portion. An actuator mechanically coupled to the back side of the movable mirror moves the inner bend resistant portion relative to the second surface of the top mirror.

Abstract: An acousto-optic (AO) device includes an AO interaction crystal for receiving and propagating a light ray along an optical propagation direction (OPD). A piezoelectric transducer is on at least one surface of the AO interaction crystal for receiving an electrical signal and emitting an acoustic wave into the AO interaction crystal. An electrode is on the piezoelectric transducer for coupling the electrical signal to the piezoelectric transducer. The electrode is a patterned electrode that includes a plurality of different transverse edge positions. The plurality of different transverse edge positions span a position range of at least five percent of an average height (Havg) of the electrode.

Abstract: An optical combination includes an input lens having an optical axis for receiving incoming rays, an output Petzval lens combination including spaced apart doublet lenses L3 and L4 both aligned along the optical axis, and an acousto-optic tunable filter (AOTF) that defines an input side and an output side for the optical combination positioned between the input lens and L3. An input aperture stop is on the input side and an output beam stop is on or near L4. The input lens can be an input Petzval lens combination including spaced apart doublet lenses L2 and L1, wherein the input aperture stop is on or near L2, and the input Petzval lens combination and output Petzval lens combinations are aligned back-to-back.

Abstract: An acousto-optic (AO) device includes an AO interaction crystal for receiving and propagating a light ray along an optical propagation direction (OPD). A piezoelectric transducer is on at least one surface of the AO interaction crystal for receiving an electrical signal and emitting an acoustic wave into the AO interaction crystal. An electrode is on the piezoelectric transducer for coupling the electrical signal to the piezoelectric transducer. The electrode is a patterned electrode that includes a plurality of different transverse edge positions. The plurality of different transverse edge positions span a position range of at least five percent of an average height (Havg) of the electrode.

Abstract: A thermally compensated optical device includes in an optical path an input linear polarizer for transmitting linearly polarized light from a received light beam at a design wavelength. A composite reciprocal rotator includes a first reciprocal material and at least a second reciprocal material provides a reciprocal rotation having a temperature coefficient for reciprocal rotation (tempcorr). At least one Faraday rotator provides a non-reciprocal rotation having a temperature coefficient for non-reciprocal rotation (tempconr). An output linear polarizer transmits forward light received after transmission by the Faraday rotator. At a design temperature, the tempcorr and tempconr have opposite signs and can have magnitudes that match within 50%.

Abstract: A system for measuring an optical spectral response of a photoelectric DUT includes a spectrally programmable light source including a broadband light source, a dispersive element for dispersing the light, and a spatial light modulator for controlling an intensity and a spectra of the light to provide a spectrally programmable light beam. A light distributing device is coupled to receive the spectrally programmable light beam and includes a light distributing structure for distributing the spectrally programmable light beam in a known ratio to a first area and a second area. A reference detector is positioned at the first area, and the DUT is positioned at the second area. Data acquisition electronics and a processor receive simultaneously generated output signals from the DUT and the reference detector to correct for intensity variation in the spectrally programmable light beam in determining the optical spectral response of the DUT.

Abstract: An optical combination includes an input lens having an optical axis for receiving incoming rays, an output Petzval lens combination including spaced apart doublet lenses L3 and L4 both aligned along the optical axis, and an acousto-optic tunable filter (AOTF) that defines an input side and an output side for the optical combination positioned between the input lens and L3. An input aperture stop is on the input side and an output beam stop is on or near L4. The input lens can be an input Petzval lens combination including spaced apart doublet lenses L2 and L1, wherein the input aperture stop is on or near L2, and the input Petzval lens combination and output Petzval lens combinations are aligned back-to-back.

Abstract: A thermally compensated optical device includes in an optical path an input linear polarizer for transmitting linearly polarized light from a received light beam at a design wavelength. A composite reciprocal rotator includes a first reciprocal material and at least a second reciprocal material provides a reciprocal rotation having a temperature coefficient for reciprocal rotation (tempcorr). At least one Faraday rotator provides a non-reciprocal rotation having a temperature coefficient for non-reciprocal rotation (tempconr). An output linear polarizer transmits forward light received after transmission by the Faraday rotator. At a design temperature, the tempcorr and tempconr have opposite signs and can have magnitudes that match within 50%.

Abstract: A system for measuring an optical spectral response of a photoelectric device under test (DUT) includes a spectrally programmable light source including in optically coupled sequence a broadband light source for emitting light, a dispersive element for dispersing light, and a spatial light modulator for controlling an intensity and a spectra of the light to provide a spectrally programmable light beam. A light distributing device having at least one input portion is coupled to receive the spectrally programmable light beam and includes a light distributing structure for distributing the spectrally programmable light beam in a known ratio to a first area and at least a second area. A reference detector having a reference output positioned at the first area, and the DUT is positioned at the second area.

Abstract: An acousto-optic (AO) frequency shifter includes an anisotropic crystal having an optical axis and an input face, and an acoustic transducer having electrodes affixed to the face for receiving an electrical signal and projecting an acoustic wave into the crystal. The anisotropic crystal is cut relative to the face so that the transducer is at an acoustic angle (?a) corresponding to a predetermined angle of incidence (?i) of an optical beam to be directed relative to the optic axis of the anisotropic crystal to substantially satisfy the parallel tangents phase matching condition.

Abstract: A fiber intensity reducer comprises a guided system fiber including a core and an outer cladding layer, an unguided fiber intensity reducing (FIR) section including a first fiber “end cap fiber” having a first end and a second end attached at its first end to the system fiber. A bond region is between the first end of the first fiber and the system fiber. The FIR section provides a softening point of at least 700° C. throughout and provides a sufficient transverse dimension along its entire length so that a beam of radiation received from the system fiber expanding therein avoids an interface with the air along its entire length. In one arrangement, the FIR section includes an outer capillary on the end cap fiber, wherein the capillary and the end cap fiber provide refractive index matching.

Abstract: An acousto-optic (AO) frequency shifter includes an anisotropic crystal having an optical axis and an input face, and an acoustic transducer having electrodes affixed to the face for receiving an electrical signal and projecting an acoustic wave into the crystal. The anisotropic crystal is cut relative to the face so that the transducer is at an acoustic angle (?a) corresponding to a predetermined angle of incidence (?i) of an optical beam to be directed relative to the optic axis of the anisotropic crystal to substantially satisfy the parallel tangents phase matching condition.

Abstract: An acoustic transducer comprises a ferroelectric crystal having a plurality of spaced apart ferroelectric domain inverted regions and at least one non-inverted region. An electrode layer is disposed on one side of the crystal electrically contacting both the domain inverted portion and the non-inverted portion of the crystal. On a side of the crystal opposite the electrode layer, a first electrode is disposed on the domain inverted portion spaced apart from a second electrode disposed on the non-inverted portion. As a result, the acoustic transducer provides sub-transducers hooked in series having effective areas defined by the areas of their respective electrodes.

Abstract: An acousto-optic modulator includes a (100), (010) or (001) single crystal silicon acousto-optic interaction medium, and at least one transducer for emitting an acoustic wave attached to the single crystal. The transducer has a first electrode layer disposed on one side and a second electrode layer disposed on its other side. The transducer is aligned to the single crystal so that the direction of acoustic propagation in the silicon crystal is substantially along the (100), (010) or (001) direction. A q-switched laser includes a modulator according to the invention.

Abstract: An acoustic transducer comprises a ferroelectric crystal having a plurality of spaced apart ferroelectric domain inverted regions and at least one non-inverted region. An electrode layer is disposed on one side of the crystal electrically contacting both the domain inverted portion and the non-inverted portion of the crystal. On a side of the crystal opposite the electrode layer, a first electrode is disposed on the domain inverted portion spaced apart from a second electrode disposed on the non-inverted portion. As a result, the acoustic transducer provides sub-transducers hooked in series having effective areas defined by the areas of their respective electrodes.

Abstract: An acousto-optic (AO) device for generating a highly apodized acoustic wave field includes a piezoelectric transducer crystal for emitting an acoustic wave having a ground electrode disposed on one side of the piezoelectric crystal, and a patterned electrode layer disposed on a side of the piezoelectric crystal opposite the ground electrode. The patterned electrode layer includes a continuous region proximate to its center and a discontinuous region, a pattern in the discontinuous region including a plurality of spaced apart features electrically connected to the continuous region. An AO interaction crystal which receives the acoustic wave is attached to the ground electrode or the patterned electrode layer.

Abstract: An acousto-optic modulator includes a (100), (010) or (001) single crystal silicon acousto-optic interaction medium, and at least one transducer for emitting an acoustic wave attached to the single crystal. The transducer has a first electrode layer disposed on one side and a second electrode layer disposed on its other side. The transducer is aligned to the single crystal so that the direction of acoustic propagation in the silicon crystal is substantially along the (100), (010) or (001) direction. A q-switched laser includes a modulator according to the invention.

Abstract: Apparatus for producing signal frequency shifts by stimulated Brillouin scattering comprises a pair of optical fibres (112,113) or a single high birefringence fibre which are illuminated by a laser beam to generate two back-scattered signals by stimulated Brillouin scattering and a mixer (117) to combine the two back-scattered signals to produce a beat frequency from the combined signals.