A hybrid design approach of optical phased array with wide beam steering range and low side-lobe level

In this paper, a new design approach of optical phased array (OPA) with low side lobe level (SLL) and wide angle steering range is proposed. This approach consists of two steps. Firstly, a nonuniform antenna array is designed by optimizing the antenna spacing distribution with particle swarm optimization (PSO). Secondly, on the basis of the optimized antenna spacing distribution, PSO is further used to optimize the phase distribution of the optical antennas when the beam steers for realizing lower SLL. Based on the approach we mentioned, we design a nonuniform OPA which has 1024 optical antennas to achieve the steering range of ±60°. When the beam steering angle is 0°, 20°, 30°, 45° and 60°, the SLL obtained by optimizing phase distribution is −21.35, −18.79, −17.91, −18.46 and −18.51 dB, respectively. This kind of OPA with low SLL and wide angle steering range has broad application prospects in laser communication and lidar system.

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Side-lobe Level Reduction of an Optical Phased Array Using Amplitude and Phase Modulation of Array Elements Based on Optically Injection-Locked Semiconductor Lasers

Photonics ◽

10.3390/photonics7010020 ◽

2020 ◽

Vol 7 (1) ◽

pp. 20

Author(s):

Anh Hang Nguyen ◽

Jun-Hyung Cho ◽

Ho-Jun Bae ◽

Hyuk-Kee Sung

Keyword(s):

Semiconductor Lasers ◽

Power Efficiency ◽

High Performance ◽

Phased Array ◽

Beam Steering ◽

Side Lobe ◽

Real Field ◽

Side Lobe Level ◽

Amplitude Profile ◽

Optical Phased Array

The side-lobe level (SLL) in optical phased array (OPA) systems should be reduced to ensure their high performance. We investigate theoretically the performance of an OPA based on optically injection-locked (OIL) semiconductor lasers. The phase and amplitude of the OIL laser are modulated by controlling the injection-locking parameters to reduce the SLL as well as to achieve beam steering. We successfully achieved an SLL reduction of >16 dB when compared with the uniform amplitude profile based on the application of the Taylor window function profile to the injection-locked OPA elements. The reduced SLL and high power efficiency achieved in this study can expedite the use of OPA in real field applications, such as free-space communication, imaging, and light detection and ranging (LIDAR).

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Wide-Angle Beam-Steering Using an Optical Phased Array with Non-Uniform-Width Waveguide Radiators

Photonics ◽

10.3390/photonics7030056 ◽

2020 ◽

Vol 7 (3) ◽

pp. 56

Author(s):

Youngin Kim ◽

Hyeonho Yoon ◽

Jong-Bum You ◽

Minchul Kim ◽

Hyo-Hoon Park

Keyword(s):

Phased Array ◽

Beam Steering ◽

Side Lobe ◽

Phase Shifters ◽

Wide Angle ◽

Half Wavelength ◽

Electro Optic ◽

Optical Phased Array ◽

Diffraction Patterns ◽

Silicon Based

We demonstrate wide-angle beam-steering using an optical phased array (OPA) with waveguide radiators designed with non-uniform widths to reduce the crosstalk between waveguides. The OPA consists of a silicon based 1 × 16 array of electro-optic phase shifters and end-fire radiators. The 16 radiators were configured with four different widths and a half-wavelength spacing, which can remove the higher-order diffraction patterns in free space. The waveguides showed a low crosstalk of −10.2 dB at a wavelength of 1540 nm. With phase control, the OPA achieved wide beam-steering of over ±80° with a side-lobe suppression of 7.4 dB.

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