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US 6,636,306 B2Granted
Optical spectrum analyzer
AssigneeEXFO Electro-Optical Engineering Inc.
InventorsGang He, Daniel Gariépy, Gregory Walter Schinn
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AssigneeEXFO Electro-Optical Engineering Inc.
InventorsGang He, Daniel Gariépy, Gregory Walter Schinn
Estimating the term…
An optical spectrum analyzer comprises a diffraction grating (DG), a polarization decomposing unit (PDM) for decomposing the input light beam into first and second light beams having mutually-perpendicular linear states of polarization, and two output ports (FP2/1, FP2/2) each for receiving from the grating, substantially exclusively, a respective one of the polarized light beams (LT, LR) after diffraction by the diffraction grating (DG). Each of the linearly-polarized light beams is directed onto the diffraction grating with its linear state of polarization at any prescribed angle to a corresponding plane of diffraction of the diffraction grating The arrangement is such that the state of polarization of the light beams, at any particular wavelength within an operating band of the analyzer remains substantially unchanged with respect to time, The analyzer also may have a reflector (RAM) for reflecting the light beams leaving the diffraction grating after diffraction a first time so as to return them to the diffraction grating for diffraction a second time.
An optical spectrum analyzer comprising a diffraction grating (DG), input means (I1,I2) comprising means (PDM) for decomposing an input light beam to provide first and second light beams (LR,LT) each having a linear state of polarization corresponding to a respective one of two mutually-perpendicular linear states of polarization of the input light beam, and means (I1,I2) for directing the first and second light beams onto the diffraction grating (DG), and output means for directing the first and second lights beams after diffraction to two output ports (O1,O2) such that each port receives substantially exclusively a respective one of the light beams at or about a selected wavelength after diffraction by the diffraction grating, the arrangement being such that, at any particular wavelength within an operating band of the analyzer, the state of polarization of each of the first and second light beams remains substantially unchanged with respect to time.
A monochromator comprising a diffraction grating (DG), means (I1,I2) for directing first and second light beams (LR,LT) having mutually-perpendicular linear states of polarization onto the diffraction grating (DG), and two output ports (O1,O2) each for receiving substantially exclusively a respective one of the linearly-polarized light beams at or about a selected wavelength after diffraction by the diffraction grating (DG), the arrangement being such that, at a particular wavelength, the state of polarization of each of the first and second light beam is preserved.
An optical spectrum analyzer comprising:
Dependencies are inferred from the claim text.