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US 8,265,112 B2Granted
Semiconductor laser device and circuit for and method of driving same
AssigneeKaiam Corp.
InventorsGideon Yoffe, Bardia Pezeshki, Thomas P. Schrans
Life of this patent
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Abstract
A directly driven laser includes multiple contacts, with at least one of the contacts for injecting current into the laser such that the laser reaches at least a lasing threshold and at least one of the contacts for providing a data signal to the laser. In some embodiments a differential data signal is effectively provided to a front and a rear section of the laser, while lasing threshold current is provided to a central portion of the laser.
Claims22
A distributed feedback (DFB) laser, comprising:
- a waveguide including an active region, with a grating in or about the waveguide, the waveguide having a longitudinal length in a direction between a front facet and a rear facet, the waveguide being generally about layers forming a p-n junction, and an anode electrical contact and a cathode electrical contact;
- with at least one of the anode electrical contact and the cathode electrical contact having a longitudinal length in the direction between the front facet and the rear facet less than the longitudinal length of the active region;
- wherein the at least one of the anode electrical contact and the cathode electrical contact having a longitudinal length in the direction between the front facet and the rear facet less than the longitudinal length of the active region extends along a front portion of the longitudinal length, the front portion being towards the front facet;
- wherein the at least one of the anode electrical contact and the cathode electrical contact having a longitudinal length in the direction between the front facet and the rear facet less than the longitudinal length of the active region is the anode electrical contact;
- and
- further comprising a further anode electrical contact, the further anode electrical contact having a longitudinal length in the direction between the front facet and the rear facet less than the longitudinal length of the active region, with the further anode electrical contact extending along a rear portion of the longitudinal length, the rear portion being towards the rear facet.
3 more elements
A distributed feedback (DFB) laser, comprising:
- a waveguide including an active region, with a grating in or about the waveguide, the waveguide having a longitudinal length in a direction between a front facet and a rear facet, the waveguide being generally about layers forming a p-n junction, and an anode electrical contact and a cathode electrical contact;
- with at least one of the anode electrical contact and the cathode electrical contact having a longitudinal length in the direction between the front facet and the rear facet less than the longitudinal length of the active region;
- and
- wherein the grating includes a phase shift longitudinally under the at least one of the anode electrical contact and the cathode electrical contact having a longitudinal length in the direction between the front facet and the rear facet less than the longitudinal length of the active region.
1 more element
A method of operating a laser, comprising:
- providing a data current signal into a first longitudinal portion of the laser and not providing the data current signal into a second longitudinal portion of the laser;
- and
- providing a bias current signal into the second longitudinal portion of the laser and not providing the bias current signal into the first longitudinal portion of the laser.
A method of operating a laser, comprising:
- providing a differential signal to a pair of gain stages within a package containing the laser, the differential signal providing a data signal, the pair of gain stages providing a signal to a front portion of the laser and/or a rear portion of the laser depending on state of the differential signal;
- and
- providing a bias signal to a central portion of the laser.
A laser and drive circuitry, comprising:
- a laser with a first electrical contact and a second electrical contact, each for provision of current signals to the laser, and a contact coupled to ground;
- a dc current source coupled to the first electrical contact;
- a data signal driver coupled to the second electrical contact;
- wherein the laser includes a third electrical contact for provision of current signals to the laser, with the data signal driver coupled to the third electrical contact;
- wherein the third electrical contact is longitudinally near the rear facet, the second electrical contact is longitudinally near the front facet, and the first electrical contact is longitudinally between the third electrical contact and the second electrical contact;
- and
- wherein the data signal driver is configured to provide a differential signal over a differential signal line.
4 more elements
Dependencies are inferred from the claim text.