Semiconductor laser device and circuit for and method of driving same

• US 8,913,638 B2
• Filed: 08/23/2012
• Issued: 12/16/2014
• Est. Priority Date: 03/26/2009
• Status: Active Grant

• Current Assignee: T&S Communications Co.,Ltd.
• Original Assignee: Kaiam Corp.
• Inventors: Yoffe, Gideon, Pezeshki, Bardia, Schrans, Thomas P.
• Primary Examiner(s): Rodriguez, Armando
• Application Number:
  US13/593,142
• Publication Number:
  US 20130003767A1
• Time in Patent Office: 845 Days
• Field of Search: 372/38.02, 372/46.01, 372/87, 372/96
• US Class Current: 372/38.02
• CPC Class Codes: H01S 5/028 Coatings ; Treatment of the laser facets, e.g. etching, passivation layers or reflecting layers
• CPC Class Codes: H01S 5/0428 for applying pulses to the laser
• CPC Class Codes: H01S 5/06226 Modulation at ultra-high frequencies
• CPC Class Codes: H01S 5/06258 with DFB-structure
• CPC Class Codes: H01S 5/12 the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers comprising a photonic bandgap structure H01S5/11; surface-emitting lasers H01S5/18
• CPC Class Codes: H01S 5/124 incorporating phase shifts
• CPC Class Codes: H01S 5/125 Distributed Bragg reflector [DBR] lasers

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.

Claims

1. 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 grating extending through the longitudinal length of the waveguide, the grating including a phase shift closer to the front facet then the rear facet, and 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 being closer to the front facet than the rear facet, and having a longitudinal length in the direction between the front facet and the rear facet less than the longitudinal length of the active region.

2. The DFB laser of claim 1, 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.

3. A distributed feedback (DFB) laser, comprising:

a waveguide including a longitudinal active region and a longitudinal non-absorbing 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 grating extending through the longitudinal length of the waveguide and including a phase shift closer to the front facet then the rear facet, and 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 being closer to the front facet than the rear facet, and having a longitudinal length in the direction between the front facet and the rear facet approximately the longitudinal length of the active region.