Method of coupling optical signal optically with optical waveguide through two lens system

• Main Authors: Kurokawa, Munetaka, Saeki, Tomoya, Shiozaki, Manabu, Fujimura, Yasushi, Yamaji, Kazuhiro
• Format: Patent
• Language: English
• Published: 21.08.2018
• Subjects: DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; FREQUENCY-CHANGING; MULTIPLEX COMMUNICATION; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PERFORMING OPERATIONS; PHYSICS; PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCESIN A PLASTIC STATE; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; TRANSMISSION; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

An optical coupling system to couple a collimated beam with a waveguide made of semiconductor materials is disclosed. The waveguide is implemented in an optical modulator and/or an optical hybrid, and has a core with a restricted cross section because of the enhanced refractive index of the semiconductor materials. The collimated beam is focused on the core by the two-lens system including first and second lenses. The first lens, having a focal length shorter than a focal length of the second lens, is first aligned with the core, then, the second lens is aligned with the core as compensating deviations of the first lens induced during the fixation thereof.