Thyristor-based optical flip-flop
View Patent ↗An optical flip-flop circuit that includes an optical thyristor configured to receive a digital optical signal input and produce a digital signal output based on the ON/OFF state of the digital optical signal input. The optical flip-flop circuit further includes control circuitry operably coupled to the terminals of the optical thyristor. The control circuitry is configured to control switching operation of the optical thyristor in response to the level of a digital electrical signal input.
1. An optical flip-flop circuit comprising:
an optical thyristor configured to receive a digital optical signal input and produce a digital signal output based on the digital optical signal input, wherein the optical thyristor is defined by an epitaxial layer structure that includes a bottom n-type cathode region, an intermediate p-type region formed above the bottom n-type cathode region, an intermediate n-type region formed above the intermediate p-type region, and a top p-type anode region formed above the intermediate n-type region, and wherein the optical thyristor includes an anode terminal electrically coupled to the top p-type anode region, an n-type injector terminal electrically coupled to the intermediate n-type region, a p-type injector terminal electrically coupled to the intermediate p-type region, and a cathode terminal electrically coupled to the bottom n-type cathode region; and
a control circuit coupled to the optical thyristor, the control circuit comprising:
a first field-effect transistor having a source terminal connected to a positive voltage supply, a gate terminal for receiving an inverted version of a digital electrical signal input, and a drain terminal connected to the n-type injector terminal; and
a second field-effect transistor having a drain terminal connected to the p-type injector terminal, a gate terminal that receives the digital electrical signal input, and a source terminal connected to ground, wherein the control circuit is configured to control a switching operation of the optical thyristor in response to a level of the digital electrical signal input.
2. The optical flip-flop circuit of claim 1 , wherein the digital signal output produced by the optical thyristor is a digital optical signal output.
3. The optical flip-flop circuit of claim 1 , wherein: the digital signal output produced by the optical thyristor is a digital electrical signal output.
4. The optical flip-flop circuit of claim 1 , wherein the first field-effect transistor is a p-channel HFET transistor.
5. The optical flip-flop circuit of claim 1 , wherein the second field-effect transistor is an n-channel HFET transistor.
6. The optical flip-flop circuit of claim 1 , wherein the digital signal output is a digital electrical signal output, and wherein the optical thyristor produces the digital electrical signal output at the cathode terminal.
7. The optical flip-flop circuit of claim 6 , wherein the optical thyristor produces an inverted version of the digital electrical signal output at the anode terminal.