The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 30, 2004
Filed:
Mar. 15, 2002
Saif M. Islam, Santa Clara, CA (US);
Shih-Yuan Wang, Palo Alto, CA (US);
Gazillion Bits, Inc., San Jose, CA (US);
Abstract
A ballast-powered semiconductor optical amplifier (SOA) apparatus and related methods are described. The SOA comprises a signal waveguide for guiding an optical signal along a signal path, and further comprises one or more ballast lasers positioned with respect to the signal waveguide such that the optical signal is amplified using energy from the lasing fields of the one or more ballast lasers. The problem of relative intensity noise (RIN) transfer from the ballast lasers into the optical signal is avoided by ensuring that the relaxation oscillation frequency (ROF) of each ballast laser is sufficiently higher than the signal modulation rate such that the RIN spectrum is tolerably low at the signal modulation rate. The ROFs themselves are manipulated by methods including adjustment of excitation current densities within the ballast lasers. In multiple-ballast laser embodiments, improvements in amplified spontaneous noise (ASE) performance are achieved where the optical signal gain per unit distance is higher near the SOA input and lower near the SOA output. Embodiments are also described in which multi-segment ballast lasers are used and in which operating points are found that satisfy the RIN noise, ASE noise, and output saturation power criteria.