A novel method to stretch light pulses is proposed by using the free-space coupling technique,with which the ultrashort laser pulses can excite ultrahigh-order modes in the symmetrical metal-cladding optical waveguide with sub-millimeter scale.

In this paper,a novel electro-optic modulator based on free space coupling technology is proposed.

Excitation of the ultrahigh-order modes are implemented by employing the free-space coupling technique.

Developments of free-space quantum key distribution;

Study on quantum key bit rate in free-space quantum cryptography;

Developments of free-space quantum cryptography;

Key techniques of free space laser communication;

The design of optical free space communication system with the optical fiber coupling system;

Spectral and temporal properties of spatially and spectrally partially coherent Gaussian Schell-model pulsed beams in free space;