John M Hegarty

46716211, Jun 9, 1987

Apr 29, 1985

6/728669

Joseph F. Dillon - Morristown NJ
John Hegarty - Gillette NJ
Raymond Wolfe - New Providence NJ

American Telephone and Telegraph Company, AT&T Bell Laboratories

G02B 2700

350403

An optical system, e. g. , an optical fiber communication system or an optical mass storage device, which includes a linearly birefringent polarization rotator useful in an optical isolator or optical circulator, is disclosed. The rotator, which compensates for the effects of linear birefringence and is substantially antireciprocal, includes two or more material regions which are capable of subjecting incident light to elliptic birefringences. However, the sign and/or magnitude of the linear, or the sign and/or magnitude of the circular, components of the elliptic birefringences differ from region to region. Moreover, the length of each region, except the first or last region, is substantially equal to one-half the birefringent period of the region. The length of the first or last region, by contrast, is substantially equal to one-quarter the birefringent period of the region.

47623845, Aug 9, 1988

Aug 30, 1985

6/771016

John Hegarty - Plainfield NJ
Raymond Wolfe - New Providence NJ

American Telephone and Telegraph Company, AT&T Bell Laboratories - Murray Hill NJ

G02B 610
G02B 2700

350 9612

An optical system, e. g. , an optical fiber communication system or an optical mass storage device, which includes a linearly birefringent polarization rotator useful in an optical isolator or optical circulator, is disclosed. The rotator, which compensates for the effects of linear birefringence and is substantially antireciprocal, includes two or more material regions which are capable of subjecting incident light to elliptic birefringences. However, the sign and/or magnitude of the linear, or the sign and/or magnitude of the circular, components of the elliptic birefringences differ from region to region. Moreover, the length of each region, except the first or last region, is substantially equal to one-half the birefringent period of the region. The length of the first or last region, by contrast, is substantially equal to one-quarter the birefringent period of the region.

48200166, Apr 11, 1989

Feb 21, 1986

6/832457

Leonard G. Cohen - Berkeley Heights NJ
John Hegarty - Summit NJ

American Telephone and Telegraph Company, AT&T Bell Laboratories - Murray Hill NJ

G02B 628
G02F 117

350 9629

An optical system, including a waveguide such as an optical fiber, in which optical signals are noninvasively coupled into the waveguide at any point along the length of the waveguide, is disclosed. This is achieved by coupling substantially constant intensity electromagnetic radiation into the waveguide, and then impinging upon the waveguide a directed beam of energy, such as electromagnetic radiation or heat, from an energy source. Alternatively, the waveguide is impinged upon by a combination of an energy beam and a stimulus, e. g. , a temperature change. The energy beam, or energy beam and stimulus, induce at least partial absorption of the guided, substantially constant intensity electromagnetic radiation by radiation-absorbing material in the waveguide, to produce the desired optical signal.