Photocarrier delay line

Abstract

The invention discloses a photocarrier delay line. The photocarrier delay line comprises an excitation laser 1, a first lens 2, semi-conductor material 3, a detection laser 4, a second lens 5 and a photoelectric detector 6, wherein a radio frequency electric signal S (t) modulates the excitation laser 1; modulated exciting light is irradiated on the semi-conductor material 3 after the exciting light is focused through the first lens 2; a non-equilibrium carrier the concentration of which changes along with the modulated exciting light is generated in the semi-conductor material 3 and radiates in all directions, and changes of concentration of the carrier can cause changes of the refractive index of the material; after detecting light emitted by the detection laser 4 is focused through the second lens 5, the detecting light is irradiated at a certain position in a reflection range of the carrier in the semiconductor material 3 at an incidence angle beta, and emergent light of the detecting light through the semi-conductor material 3 carries delayed information of an exciting light signal; and the emergent light is converted into a radio frequency electric signal V(t) through the photoelectric detector 6, and the signal V(t) is the delayed radio frequency electric signal S(t).

Description

technical field [0001] The invention relates to the technical field of delay lines, in particular to an optical carrier delay line. Background technique [0002] A delay line is an element or device used to delay a signal for a period of time. The delay line should have flat amplitude-frequency characteristics and certain phase shift characteristics (or delay frequency characteristics) in the passband. Delay lines are widely used in radars, electronic computers, color television systems, communication systems, and measuring instruments (such as oscilloscopes). [0003] Delay lines can be divided into three types: one is electrical signal delay lines, such as charge-coupled devices (CCD) and cables, etc.; the other is ultrasonic delay lines, such as mercury delay lines, quartz delay lines, etc.; the third is optical signal delay lines, such as Optical delay line, optical digital synchronous delay line memory, etc. Their delays range from a few nanoseconds to tens of micros...

AI Technical Summary

Problems solved by technology

Since the path length changes incrementally, the delay time can only be incremental rather than continuous, and the accuracy is on the order of tens of picoseconds to hundreds of picoseconds, which greatly limits the application range of optical delay lines.

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