Abstract: A tunable laser system utilizes a frequency shift compensated acousto-optic tunable filter. The wavelength accuracy and stability is achieved by a wavelength locker utilizing two separate intracavity light beams without the need to use beam splitters to significantly reduce the space typically needed by a conventional wavelength locker, and provide more stable operation and easy assembly. The acoustic optical tunable filter includes an acousto-optical crystal with a transducer coupled to the crystal to generate acoustic waves, and an optical mirror to reflect the diffracted light beam back to the acousto-optical medium again such that the frequency shift by two diffractions is compensated. By using different laser gain mediums, acoustic wave driving frequencies and acousto-optical crystals, this invention can be used to make tunable lasers in wide range of optical wavelengths for many different applications.

Abstract: An integrated optical device functioning as optical isolator, shutter, variable optical attenuator, and modulator is disclosed. The device employs a Pockels cell for dynamically rotating with nanosecond speed the polarization state of incident light for attenuation and modulation. The invention provides a compact, high performance and reliable device without moving parts for use in laser systems and particularly in fiber optic telecommunication system.

Abstract: A tunable laser cavity utilizes a dispersion compensated acousto-optic tunable filter. The wavelength accuracy and stability is achieved by a wavelength locker utilizing two separate intracavity light beams without the need to use beam splitters to significantly reduce the space typically needed by a conventional wavelength locker, and provide more stable operation and easy assembly. The acoustic optical tunable filter is constructed in such a way that two transducers are bonded on the same crystal opposite to each other to create two counter propagating acoustic waves. Dispersion occurs after the collimated light diffracted by the first acoustic wave and is compensated by the second acoustic wave traveling in the opposite direction. By using different laser gain mediums, acoustic wave driving frequencies and acousto-optical crystals, this invention can be used to make tunable lasers in wide range of optical wavelengths.

Abstract: A scalable reconfigurable (or tunable) optical add/drop multiplexer (SROADM) is disclosed. The SROADM includes a pair of acoustic optic tunable filters (AOTF) and a wavelength blocker (WB). A first input port receives an initial wavelength division multiplexer (WDM) optical signal including to-be-dropped optical signal(s). A second input port(s) receives optical signal(s) to be added, which has the same wavelength(s) as that optical signal(s) to be dropped. In one embodiment, the WB is connected to the AOTFs through free space coupling. In another embodiment, the coupling is achieved by optical fiber fusion splicing. The latter method has advantage of using commercially available products and easier assembly while a more compact size is achievable by the free space coupling. The device is scalable in terms of number of add/drop ports and capacity to process any number of wavelength channels.

Abstract: An acousto-optical tunable filter is disclosed. The filter includes a medium having one or more indices of refractions alterable by the application of acoustic waves to the medium. The filter also includes an acoustic transducer coupled to the medium to generate the acoustic waves Altering the frequency of the acoustic wave selects among the different wavelengths in the incident light ray. The device also includes an optical mirror for reflecting a wave diffracted by the medium back to the medium so that it can again be diffracted. The first diffracted wave has its frequency shifted in one direction by the frequency of the acoustic wave while the second diffracted wave has its frequency shifted in the opposite direction, thereby compensating for the first shift. The result is an output ray with little or no frequency shift.

Abstract: An integrated optical device functioning as optical isolator, shutter, variable optical attenuator, and modulator is disclosed. The device employs a Pockels cell for dynamically rotating with nanosecond speed the polarization state of incident light for attenuation and modulation. The invention provides a compact, high performance and reliable device without moving parts for use in laser systems and particularly in fiber optic telecommunication system.