Optical external modulator for optical telecommunications
First Claim
1. An optical external modulator characterized in that it comprises a substrate (1), an optical transmission line (7), a phase changing section (8) and a polarization modulating section (11) for changing the state of polarization of the light being propagated through the optical transmission line (7) by applying a stress to the optical transmission line (7) as a function of a modulation signal given thereto and the phase changing section (8) for changing the phase difference between the X-component and the Y-component of the light being propagated through the optical transmission line (7) by (2m-1)*π
- /2 (m is a positive integer).
1 Assignment
0 Petitions
Accused Products
Abstract
There is provided an optical external modulator that can modulate the polarization of incident light without regulating the state of polarization of the light entering the modulator. Such a modulator can be suitably incorporated into an optical telecommunications system. An optical external modulator according to the invention comprises a substrate 1, an optical transmission line 7, a polarization modulating section 11 and a phase changing section 8 for changing the state of polarization of the light passing through the optical transmission line by applying stress to the optical transmission line 7 as a function of a modulation signal given to the modulator such that the phase difference between the X-component and the Y-component of the light being propagated through the optical transmission line 7 is shifted by (2m-1)*π/2 (m is a positive integer).
38 Citations
15 Claims
-
1. An optical external modulator characterized in that it comprises a substrate (1), an optical transmission line (7), a phase changing section (8) and a polarization modulating section (11) for changing the state of polarization of the light being propagated through the optical transmission line (7) by applying a stress to the optical transmission line (7) as a function of a modulation signal given thereto and the phase changing section (8) for changing the phase difference between the X-component and the Y-component of the light being propagated through the optical transmission line (7) by (2m-1)*π
- /2 (m is a positive integer).
- View Dependent Claims (2, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
3. An optical external modulator characterized in that it comprises a substrate (1), a pair of optical transmission lines (7, 7), a phase changing section (8) and a polarization modulating section (11) for changing the state of polarization of the light being propagated through the pair of optical transmission lines (7, 7) by applying a stress to the optical transmission lines (7, 7) as a function of a modulation signal given thereto, the phase changing section (8) being arranged between the pair of optical transmission lines (7, 7) for changing the phase difference between the X-component and the Y-component of the light being propagated through the optical transmission lines (7, 7) by (2m-1)*π
- /2 (m is a positive integer).
-
4. An optical external modulator characterized in that it comprises a substrate (1), pair of optical transmission lines (7, 7), a phase changing section (8) a pair of polarization modulating sections (11, 11) for changing the state of polarization of the light being propagated through respective optical transmission lines (7, 7) arranged respectively as integral parts thereof by applying a stress to the optical transmission lines (7, 7) as a function of a modulation signal given thereto and a phase changing section (8) arranged between the pair of optical transmission lines (7, 7) for changing the phase difference between the X-component and the Y-component of the light being propagated through the optical transmission lines (7, 7) by (2m-1)*π
- /2 (m is a positive integer).
Specification