Massachusetts Institute of Technology

USA As Represented by Secretary of the Navy

Clifton G Fonstad

L Rafael Reif

Kamal Tabatabaie-Alavi

Abu N Choudhury

Nancy J Gabriel

Nancy J Slater Gabriel

Elias Towe

A method and apparatus for phase-locking semiconductor laser arrays is described wherein individual light waves propagating in adjacent waveguides are phase-locked by intercoupling the waveguides in a specific manner. The waveguides are intercoupled in an unguided mode-mixing region wherein various modes of propagation mix by diffraction. The length of this region is fixed at a distance z which produces a phase difference an integral multiple of 2.pi. between adjacent waveguides.

Phase-locked semiconductor laser arrays

A method and apparatus for forming epitaxial thin film layers on substrates having abrupt transitions between layers of different composition or layers of different or like composition with different degrees of doping included therein. Gaseous reactants containing the desired elements to be included in the first film layer are injected into a CVD reaction chamber containing a substrate. The substrate is heated to a temperature high enough to obtain an epitaxial deposit, but low enough so as not to cause decomposition of the reactants. Once the gaseous reactant flows reach steady-state, an electric discharge or plasma is created in the gases to initiate the decomposition reaction and obtain a deposit. In this way, no transient effects are present. Once the deposit has attained sufficient thickness, the electric discharge is turned off to abruptly terminate deposition. phase composition is then established for the next film to be deposited before again generating plasma in the gas reactants to deposit an epitaxial film of different composition or different degree of doping on top of the previous one.

Growth of epitaxial films by chemical vapor deposition

A method and apparatus for forming epitaxial thin film layers on substrates having abrupt transitions between layers of different composition or layers of different or like composition with different degrees of doping included therein. Gaseous reactants containing the desired elements to be included in the first film layer are injected into a CVD reaction chamber containing a substrate. The substrate is heated to a temperature high enough to obtain an epitaxial deposit, but low enough so as not to cause decomposition of the reactants. Once the gaseous reactant flows reach steady-state, an electric discharge or plasma is created in the gases to initiate the decomposition reaction and obtain a deposit. In this way, no transient effects are present. Once the deposit has attained sufficient thickness, the electric discharge is turned off to abruptly terminate deposition. A new gas-phase composition is then established for the next film to be deposited before again generating plasma in the gas reactants to deposit an epitaxial film of different composition or different degree of doping on top of the previous one.

Growth of epitaxial films by plasma enchanced chemical vapor deposition

A method for Ion implantation using multiple energy Be.sup.+ to produce p-type regions in n-In.sub.0.53 Ga.sub.0.47 As. A simple technique is used to develop capless annealing of InGaAs up to 700.degree. C. The ion implantation of silicon is then accomplished to create n.sup.+ layers in previously Be-implanted InGaAs epilayers. The active efficiency of 40% for 50 KeV Be implant has been found and efficiencies of 86% and 38% are found for the low and high energy Si implants respectively.

Dual species ion implantation of ternary compounds based on In-Ga-As

A method for obtaining a very low resistance ohmic contact on p-type Indium hosphide (InP) by light-assisted plating of Au and Zn. The plating technique, which uses alternating positive and negative current pulses, has been used for producing patterned, small area contacts on device structures and is compatible with established n-type ohmic contacting procedures.

Growing community of inventors

Arlington, MA, United States of America

Clifton G Fonstad