Abstract A Gunn effect device is utilized to provide pulses of the high amplitude and frequency needed to drive an optical modulator, such as a lithium tantalate crystal for efficiently utilizing the bandwidth of light transmitted through the modulator. An acoustically absorbent mounting is provided for the modulator to suppress acoustical ringing resulting from piezoelectric effects in the modulator. The modulation system is initially aligned by simulating at a comparatively low frequency the drive amplitudes in order to establish a maximum condition of modulation in the optical part of the system. Thereafter, signals at the Gunn effect device output rate are supplied for controlling the modulator. Information-representative signals coupled to the modulator through the Gunn effect device are synchronized with the optical system utilizing the modulator.
The combination in accordance with claim 1 in which: means in said applying means supply said voltage on a pulsed voltage bias basis at a frequency which is much lower than said repetition rate and wherein each voltage pulse duration is much longer than the period of said repetition rate.
Claim 2
Dependent Claim
65 words
A The combination in accordance with claim 1 in which: said modulator is a semiconductor member mounted between electrical contacts extending over substantially the full extent of opposed faces thereof to form a significant circuit capacitance; said semiconductor device is electrically connected between said electrical contacts for charging said capacitance in a time interval which is much shorter than the period of said repetition rate.
Claim 3
Dependent Claim
44 words
The combination in accordance with claim 1 in which said applying means comprises: means biasing said device below said threshold; and means supplying information signals at an information bit rate which is substantially said predetermined repetition rate for biasing said device over said threshold.
Claim 4
Dependent Claim
76 words
The combination in accordance with claim 4 in which: said modulator operates on a polarization rotation basis and has predetermined high slope and lower slope parts in its voltage versus rotation characteristic; said applying means biases said modulator to a predetermined nominal operating point in said high slope part of said rotation characteristic; and said supply means includes means superimposing said information signals upon the device bias for establishing net bias variations around said operating point.
Claim 5
Dependent Claim
40 words
The combination in accordance with claim 4 which comprises in addition: a light source for supplying said radiation to said modulator; and means coupling said light source and said information signal supplying means for operation in synchronism with one another.
Claim 6
Dependent Claim
48 words
The combination in accordance with claim 1 in which: said repetition rate is at least partly a function of a dimension of said device along which said domains are propagated; and said applying means further comprises means tuning said applying means for partially determining said predetermined repetition rate.
Claim 7
Dependent Claim
28 words
The combination in accordance with claim 7 in which: said tuning means comprises electric circuit connections for applying said voltage and configured to resonate at said repetition rate.