US 9,810,964 B2
Electro-optic modulator having identical forward and backward electro-optic response
Henri Porte, Serre les Sapins (FR); Alexandre Mottet, Besancon (FR); Thomas Luthi, Aarau (CH); and Burkhard Bockem, Brugg (CH)
Assigned to LEICA GEOSYSTEMS AG, Heerbrugg (CH)
Appl. No. 14/394,206
Filed by LEICA GEOSYSTEMS AG, Heerbrugg (CH)
PCT Filed Mar. 6, 2013, PCT No. PCT/CH2013/000035
§ 371(c)(1), (2) Date Oct. 13, 2014,
PCT Pub. No. WO2013/155636, PCT Pub. Date Oct. 24, 2013.
Claims priority of application No. 12405037 (EP), filed on Apr. 16, 2012.
Prior Publication US 2015/0070709 A1, Mar. 12, 2015
Int. Cl. G02F 1/01 (2006.01); G02F 1/225 (2006.01); G02F 1/035 (2006.01); G01S 17/36 (2006.01); G01S 7/481 (2006.01); G01B 9/02 (2006.01); G01B 11/14 (2006.01); G01S 17/32 (2006.01); G02F 1/365 (2006.01); G02F 1/03 (2006.01)
CPC G02F 1/2255 (2013.01) [G01B 9/02049 (2013.01); G01B 11/14 (2013.01); G01S 7/4812 (2013.01); G01S 17/32 (2013.01); G01S 17/36 (2013.01); G02F 1/0356 (2013.01); G02F 1/365 (2013.01); G02F 1/0316 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An electro-optic modulator, comprising:
a straight waveguide of a nonlinear optical material; and,
an electrode line arranged to generate an electrical field in a modulating region of the waveguide when a voltage is applied to the electrode line so as to modulate a phase of light passing through the waveguide,
wherein the electrode line comprises a first branch and a second branch, wherein each branch:
extends from a beginning to an end of a first line section parallel to the waveguide in a first direction for a first distance,
extends from the beginning to an end of a second line section parallel to the waveguide for a second distance in a second direction, said second direction being opposite to said first direction and said second distance being equal to said first distance,
wherein the first and second line sections of the branch affect a modulation subregion of the waveguide; and wherein
the electro-optic modulator comprises a signal generator configured to apply a voltage to a terminal of the electrode line, and thereby generates a microwave signal in the branches of the electrode line, wherein a frequency of the microwave signal is at or near a center frequency, the center frequency corresponding, in each branch, to a center wavelength of the microwave signal, wherein in each branch the center wavelength of the microwave signal or an integer multiple of the center wavelength, is equal to twice the first distance,
wherein the waveguide and the electrode line are configured to provide a forward electro-optic response in the modulating region and a backward electro-optic response in the modulating region, said forward and backward electro-optic responses being equal to one another, and
the waveguide and the electrode line are configured such that the forward and backward electro-optic responses have a band-pass or a low-pass characteristic.