1. A method to optimize authenticated multi-session establishment for a single supplicant, comprising:
authenticating the supplicant with an authentication server using an authenticator of the supplicant, wherein the supplicant is a wireless access point, the authenticator is a switch port coupling the access point to a backbone network coupling the switch port to the authentication server;
determining by the authentication server at least one other session for the supplicant;
initiating by the authentication server the at least one other session for the supplicant with an authenticator for the at least one other session, wherein a one of the at least one other session is established as a session between a wireless domain server and the access point;
distributing a first session key by the authentication server to the switch port for establishing a session between the access point and the switch port;
the initiating the at least one other session with the wireless domain server further comprises distributing a second session key by the authentication server to the wireless domain server; and
distributing a set of keys to the access point by the authentication server;
wherein the set of keys comprises a first key corresponding to the first session key and a second key corresponding to the second session key.
2. A method according to claim 1, wherein the determining at least one other session further comprises sending a list of the at least one other session from the supplicant to the authentication server.
3. A method according to claim 1, wherein the determining at least one other session further comprises determining that the supplicant is authorized to be initiated with the at least one other session.
4. A method according to claim 1, wherein the determining at least one other session further comprises retrieving a database entry for the supplicant by the authentication server from a database accessible to the authentication server.
5. A method according to claim 1, wherein the at least one other session is authenticated with the authentication server before the supplicant is authenticated.
6. A system, comprising:
means for authenticating a supplicant with an authentication server using an authenticator of the supplicant, wherein the supplicant is a wireless access point, the authenticator is a switch port coupling the access point to a backbone network coupling the switch port to the authentication server;
means for determining by the authentication server at least one other session for the supplicant;
means for initiating by the authentication server the at least one other session for the supplicant by the authentication server with an authenticator for the at least one other session, wherein the one of the at least one other session is established with a wireless domain server for the access point;
means for distributing a first session key by the authentication server to the switch port for establishing a session between the access point and the switch port;
the means for initiating the at least one other session with the wireless domain server further comprises means for distributing a second session key by the authentication server to the wireless domain server; and
means for distributing a set of keys to the access point by the authentication server;
wherein the set of keys comprises a first key corresponding to the first session key and a second key corresponding to the second session key.
7. A system according to claim 6, wherein the means for determining at least one other session further comprises means for sending a list of the at least one other session from the supplicant to the authentication server.
8. A system according to claim 6, wherein the means for determining at least one other session further comprises means for retrieving a database entry for the supplicant by the authentication server from a database accessible to the authentication server.
9. A system according to claim 6, wherein the means for initiating at least one other session further comprises:
means for distributing a first key for the at least one other session to an authenticator of the at least one other session; and
means for distributing a second key corresponding to the first key for the at least one other session to the supplicant.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An integrated optical device comprising:
a planar substrate,
a Mach-Zehnder modulator integrated on said substrate characterized in that it further comprises
a Y-branch optical attenuator integrated on said substrate to provide an attenuation range, said Y-branch attenuator being optically coupled to said Mach-Zehnder modulator, and
means for reducing a crosstalk between said Y-branch attenuator and said Mach-Zehnder modulator, whereby the extinction ratio of the optical device is at least 18 dB on an attenuation range of at least 6 dB.
2. An integrated optical device as in claim 1, characterized in that the extinction ratio of the optical device is at least 20 dB on an attenuation range of at least 6 dB.
3. An integrated optical device as in claim 1 or 2, characterized in that said Mach-Zehnder modulator is optically coupled to one arm of said Y-branch attenuator.
4. An integrated optical device as in claim 1 or 2, characterized in that said Mach-Zehnder modulator is optically coupled to the common waveguide of said Y-branch attenuator.
5. An integrated optical device as in claims 1 to 4, characterized in that said means for reducing comprises one arm of said Y-branch attenuator disposed parallel with respect to a longitudinal direction.
6. An integrated optical device as in claims 1 to 5, characterized in that said means for reducing comprises a filter of an unguided radiation spreading on said substrate, the filter being arranged in a region between said Y-branch attenuator and said Mach-Zehnder modulator.
7. An integrated optical device as in claim 6, characterized in that said filter comprises metal strips disposed on the side of a connecting optical waveguide coupling said Y-branch attenuator and said Mach-Zehnder modulator.
8. An integrated optical device as in claim 7, characterized in that a gap between said metal strips is about 170% of the MFD of said connecting optical waveguide.
9. An integrated optical device as in claim 7, characterized in that the length of said metal strips is about 4 mm.
10. An integrated optical device as in claim 7, characterized in that said metal strips are integrated in an extension of the electrodes of said Y-branch attenuator, so that the gap between said electrodes progressively increases from about 100% to about 170% of the MFD of said optical waveguide in a first portion of said extension and is about 170% of the MFD of said optical waveguide in a second portion of said extension.
11. An integrated optical device as in claim 10, characterized in that said second portion of said extension has a length of about 4 mm.
12. An integrated optical device as in claims 1 to 11, characterized in that said means for reducing comprises waveguides for said Y-branch attenuator having a width lower between 5% and 16% with respect to the width of the waveguides of said Mach-Zehnder modulator.
13. An integrated optical device as in claim 12, characterized in that the width of the waveguides of said Y-branch attenuator is 8% less than the width of the waveguides of said Mach-Zehnder modulator.
14. An integrated optical device comprising:
a substrate,
a Mach-Zehnder modulator integrated on said substrate characterized in that it further comprises
a Y-branch attenuator integrated on said substrate,
said Mach-Zehnder modulator being optically coupled to one arm of said Y-branch attenuator.
15. A method for reducing the crosstalk between at least two devices including optical waveguides integrated on a substrate, each of said optical devices including at least one multimodal section of optical waveguide, said crosstalk being generated by unguided optical radiation propagating on said substrate in a region comprised between said optical devices, said method comprising filtering said unguided radiation in said region.
16. A transmitting module comprising:
a laser source for emitting an optical signal,
an integrated optical device for modulating the intensity of said optical signal,
comprising a Mach-Zehnder modulator formed on a substrate,
characterized in that
said integrated optical device further comprises a Y-branch optical attenuator formed on said substrate optically coupled to said modulator, to provide an attenuation range, and
means for reducing a crosstalk between said Y-branch attenuator and said Mach-Zehnder modulator, whereby the extinction ratio of the optical device is at least 18 dB on an attenuation range of at least 6 dB.
17. A transmitting module comprising:
a laser source for emitting an optical signal,
an integrated optical device for modulating the intensity of said optical signal,
comprising a Mach-Zehnder modulator formed on a substrate,
characterized in that
said integrated optical device further comprises a Y-branch optical attenuator formed on said substrate, and
said Mach-Zehnder modulator is optically coupled to one arm of said Y-branch attenuator.
18. A transmitting module as in claim 17, characterized in that said Y-branch attenuator is located upstream with respect to said Mach-Zehnder modulator.
19. A transmitting module as in claim 17, characterized in that said Y-branch attenuator is located downstream with respect to said Mach-Zehnder modulator.
20. A transmitting module as in claim 18, characterized by that said integrated optical device comprises a dummy waveguide coupled to the second arm of said Y-branch attenuator and a feedback circuit optically connected to said dummy waveguide, said feedback circuit comprising electrical control circuits for controlling the wavelength of said emitted signal.