Query: High power coherent two-dimensional semiconductor laser array

Candidate papers:

abstract: Diffraction limited 1.4 W pulsed output power is demonstrated from a two dimensional 144 element surface emitting laser array placed in an external Talbot cavity. Phase locking of the array is achieved with a parallel phase sensing and control system based on phase contrast imaging used in combination with a liquid crystal array in the laser cavity. Diffraction limited cw operation is also demonstrated.
author_names: Steve Sanders

Robert G Waarts

Derek W Nam

David Welch

Donald R Scifres

John C Ehlert

W J Cassarly

J Michael Finlan

Kevin M Flood
title: High power coherent two dimensional semiconductor laser array
year: 1994

abstract: The design, fabrication, and testing of a two dimensional array of 900 laser diode power amplifiers injected by a single semiconductor master oscillator is discussed. This array extends the results of the 200 emitter array reported on last year. The array consists of a stack of ten 100 emitter linear arrays. Nine of the 100 emitter arrays were successfully stacked and injected by a semiconductor master oscillator laser by way of a 1 to 10 semiconductor ridge waveguide splitter and amplifier array. The tenth 100 emitter array was included in the stack but the fiber optic used to connect it to the 1 to 10 splitter broke before final strain relief was added. The 900 amplifiers produced approximately 36 W of coherent power in the near field. Poor fill optics allowed only 15.6 W to be delivered to the far field of which 5.5 W were phase aligned into a narrow beam in one axis and into 5 major spots in the other axis. Improved optics and higher power emitters are the next steps in moving this array architecture to high power and brightness.
author_names: Joseph L Levy

Kun Roh
title: Coherent array of 900 semiconductor laser amplifiers
venue: Photonics West
year: 1995

abstract: Abstract Some of the most significant and challenging goals in the advancement of surface emitting semiconductor lasers include realizing high brightness sources. A promising method for increasing the optical power is to combine or optical couple the light output of multiple lasers into a single coherent beam. There have been a variety of methods used to achieve optical coupling in two dimensional vertical cavity surface emitting lasers (VCSELs) which include injection locking, evanescent coupling, diffractive coupling, and anti guiding or leaky mode laser coupling. This chapter will focus on the physical principles of these different coupling mechanisms and how they are incorporated into two dimensional VCSEL arrays. First, a review of beam combining methods and the metrics used to quantify their performance is presented. The advantages of coherent beam combining over incoherent beam combining is shown as well as the necessity of optical coupling for establishing coherence across a laser array. The general discussion of the optical coupling physics for each method will be supplemented by specific examples of two dimensional VCSEL array coupling.
author_names: Dominic Francis Siriani

Kent D Choquette
title: Coherent Coupling of Vertical Cavity Surface Emitting Laser Arrays
year: 2012

abstract: Electronically controlled optical beam steering is sensitive and reliable. It is significant for phased laser radar applications. We reported the experimental characterization of three element coherent vertical cavity surface emitting laser arrays and demonstrated two dimensional electronical beam steering. 2 D far field patterns, near field patterns, and the spectra of the beam under different current conditions were measured. It is demonstrated that beam steering is continuous and predicted. Above 17.9% of the total power of the array is concentrated in the central lobe, showing high coupling efficiency. Up to a 3.26deg shift angle from normal is demonstrated. The beam steering mechanism of frequency detuning between the three cavities was analyzed via both theory and experiment.
author_names: Meng Xun

Yun Sun

Jing-tao Zhou

Chen Sen Xu

Yiyang Xie

Haixia Wang

Qiang Kan

Zhi Jin

Xinyu Liu

Dexin Wu
title: Two dimensional beam steering analysis in a phase coupled vertical cavity surface emitting laser array
venue: OSA Continuum
year: 2019

abstract: Mechanical free, high power, high beam quality two dimensional (2D) beam scanning lasers are in high demand for various applications including sensing systems for smart mobility, object recognition systems, and adaptive illuminations. Here, we propose and demonstrate the concept of dually modulated photonic crystals to realize such lasers, wherein the positions and sizes of the photonic crystal lattice points are modulated simultaneously. We show using nano antenna theory that this photonic nanostructure is essential to realize 2D beam scanning lasers with high output power and high beam quality. We also fabricate an on chip, circuit driven array of dually modulated photonic crystal lasers with a 10 x 10 matrix configuration having 100 resolvable points. Our device enables the scanning of laser beams over a wide range of 2D directions in sequence and in parallel, and can be flexibly designed to meet application specific demands. Beam scanning lasers are required for systems for smart mobility, object recognition, and adaptive illuminations. The authors demonstrate dually modulated photonic crystals, wherein the positions and sizes of the photonic crystal lattice points are modulated simultaneously, to achieve mechanical free, 2D beam scanning.
author_names: Ryoichi Sakata

Kenji Ishizaki

Menaka de Zoysa

Shin Fukuhara

Takuya Inoue

Yoshinori Tanaka

Kintaro Iwata

Ranko Hatsuda

Masahiro Yoshida

John Gelleta

Susumu Noda
title: Dually modulated photonic crystals enabling high power high beam quality two dimensional beam scanning lasers
venue: Nature Communications
year: 2020

abstract: A smile suppressed high power InGaN laser array has been developed for a high beam quality material processing light source. The smile effect becomes apparent especially in InGaN laser array with large chip curvature due to lattice mismatch of epitaxial growth layers. To reduce the smile, periodic grooves are introduced to the epitaxial layers for removing the origin of strain. It also enables a two dimensional strain management of remaining epitaxial layers. This technology improves the chip curvature within micron range, i.e. as small as 0.3 mm in a 9 mm width InGaN laser array. We have successfully realized reducing the smile to 0.4 mm without degrading the laser light output characteristics.
author_names: Shinichiro Nozaki

Masao Kawaguchi

Takahiro Nibu

Hiroyuki Hagino

Atsunori Mochida

Takashi Kano

S Takigawa

Takuma Katayama

Tsuyoshi Tanaka

Kouji Oomori
title: A high power InGaN laser array with built in smile suppression structure
venue: LASE
year: 2020

abstract: We demonstrate coherent beam combination of two dimensional high power fiber amplifier array using stochastic parallel gradient descent (SPGD) algorithm. Four polarization maintained fiber amplifiers are tiled side by side into a 2x2 laser array with a fill factor of 54% in the near field. Phase control on the fiber amplifiers are performed by running SPGD algorithm on a digital dignal processor with updating rate of 50 000 Hz/channel. Coherent beam combination of the four fiber amplifiers with a total output power of 60.1 W using SPGD algorithm is demonstrated. Beam quality of the combined beam is computed to be BQ<1.4.
author_names: Pu Zhou

Zejin Liu

Xiaolin Wang

Yanxing Ma

Haotong Ma

Xiaojun Xu
title: Coherent beam combination of two dimensional high power fiber amplifier array using stochastic parallel gradient descent algorithm
year: 2009

abstract: We have fabricated and operated large two dimensional (2D) arrays of phase locked surface emitting semiconductor lasers. The arrays were fabricated by reactive ion beam etching of epitaxial Fabry Perot resonators comprising GaAs/AlGaAs quantum wells surrounded by AlAs AlGaAs quarter wave mirrors. Different arrays corresponding to different pixel size (2 5 mm) and spacing (1 2 mm) were produced to investigate evanescent coupling between pixels. The arrays were photopumped so that the array size could be conveniently varied from 1x1, 2x2, up to 20x20. Except for the 1x1 which emits a circular pattern, all arrays exhibit a well defined four lobed far field pattern in agreement with our theoretical analysis of the optical modes which predicts domination by the 2D out of phase eigenmode. As a consequence this pattern can be understood with simple Fraunhofer diffraction theory. The angular spread of the lobes, determined by the periodicity of the array elements, is 10deg for the array with element size/spacing.
author_names: Paul L Gourley

Mial E Warren

G Ronald Hadley

Gregory A Vawter

Thomas M Brennan

Burrell E Hammons
title: Coherent beams from high efficiency two dimensional surface emitting semiconductor laser arrays
year: 1991

abstract: Summary form only given. The coherent output from semiconductor laser sources can be increased by coherently combining the light from an array of many individual lasers in an external Talbot cavity configuration. As the number of elements increases, the mode discrimination required for strong coherence can be maintained by using two dimensional laser arrays. Here we present results on the phase locking of a 2 dimensional 12/spl times/12 surface emitting gain array in an external Talbot cavity.<ETX>
author_names: Steve Sanders

Robert G Waarts

Derek W Nam

Dave Welch

John C Ehlert

William James Cassarly

J Michael Finlan

Kevin M Flood
title: Phase locking of a two dimensional semiconductor laser array in an external Talbot cavity
venue: Proceedings of LEOS '93
year: 1993

abstract: We demonstrate the phase locking of a 12 X 12 two dimensional surface emitting laser array to generate 1.4 W of output power in diffraction limited far field. A phase contrast imaging system is used to measure array element phases and apply corrections to an intracavity liquid crystal array.
author_names: Steve Sanders

Robert G Waarts

Derek W Nam

Dave Welch

John C Ehlert

William James Cassarly

J Michael Finlan

Kevin M Flood
title: Phase locking of a two dimensional semiconductor laser array in an external Talbot cavity
venue: Photonics West Lasers and Applications in Science and Engineering
year: 1994