Mnih V, Kavukcuoglu K, Silver D, Graves A, Antonoglou I, Wierstra D, Riedmiller M (2013) Playing Atari with deep reinforcement learning. arXiv preprint arXiv:1312.5602

Uberna R, Bratcher A, Alley TG, Sanchez AD, Flores AS, Pulford B (2010) Coherent combination of high power fiber amplifiers in a two-dimensional re-imaging waveguide. Opt Express 18:13547–13553

Jauregui C, Limpert J, Tünnermann A (2011b) On the Raman threshold of passive large mode area fibers. In: Proceedings of SPIE 7914, fiber lasers VIII: technology, systems, and applications, 791408 (10 February)

Bai Y, Lei G, Chen H, Feng X, Li D, Bai J (2019) Incoherent space beam combining of fiber-transmitted semiconductor lasers for oil well laser perforation. IEEE Access 7:154457–154465

Wang D, Du Q, Zhou T, Li D, Wilcox R (2021) Stabilization of the 81-channel coherent beam combination using machine learning. Opt Express 29:5694–5709

Tünnermann H, Shirakawa A (2020) Tiled aperture beam combining with reinforcement learning. In: 2020 conference on lasers and electro-optics (CLEO), pp 1–2

Zhu J, Zhou P, Ma Y, Xu X, Liu Z (2011) Power scaling analysis of tandem-pumped Yb-doped fiber lasers and amplifiers. Opt Express 19:18645–18654

Leger JR, Scott ML, Veldkamp WB (1988) Coherent addition of AlGaAs lasers using microlenses and diffractive coupling. Appl Phys Lett 52:1771–1773

Zhou T, Sano T, Wilcox R (2017a) Coherent combination of ultrashort pulse beams using two diffractive optics. Opt Lett 42:4422–4425

Condenser: the lens located below the stage, which focuses light (from the illuminator) through the specimen being observed. Most microscopes have a movable condenser allowing its distance from the specimen to be adjusted using the condenser knob and condenser alignment screws.

Incoherentbeam combining

Iris diaphragm: a unit below the condenser that controls the amount of light directed to the specimen. The diameter of the diaphragm can be adjusted by turning it to increase or decrease the size of the hole that light passes through.

Goodno GD, McNaught SJ, Rothenberg JE, McComb TS, Thielen PA, Wickham MG, Weber ME (2010a) Active phase and polarization locking of a 1.4 kW fiber amplifier. Opt Lett 35:1542–1544

Mar 24, 2022 — The magnification definition as used in microscopy normally takes into account the separate magnification powers of the objective lens ...

Laserbeam combiningmethods

Shekel E, Vidne Y, Urbach B (2020) 16 kW single mode CW laser with dynamic beam for material processing. In: Proceedings of SPIE 11260, fiber lasers XVII: technology and systems, p 1126021 (21 February)

Azarian A, Bourdon P, Lombard L, Jaouën Y, Vasseur O (2014) Orthogonal coding methods for increasing the number of multiplexed channels in coherent beam combining. Appl Opt 53:1493–1502

Song J, Li Y, Che D, Guo J, Wang T (2020) Coherent beam combining based on the SPGD algorithm with a momentum term. Optik 202:163650

Fu X, Brunton SL, Kutz JN (2014) Classification of birefringence in mode-locked fiber lasers using machine learning and sparse representation. Opt Express 22:8585–8597

Linslal CL, Sooraj MS, Panbiharwala Y, Padmanabhan A, Dixit A, Venkitesh D, Srinivasan B (2019) Investigation of line broadening scheme dependence on coherent beam combination efficiency. In Laser congress 2019 (ASSL, LAC, LS&C), OSA technical digest (Optical Society of America)

Anderson B, Flores A, Holten R, Dajani I (2015) Comparison of phase modulation schemes for coherently combined fiber amplifiers. Opt Express 23:27046–27060

Spectralbeam combining

Light source safety shutters can be used to block a light sources output without turning off the lamp, and to obtain radiometric zero in order to ...

A compound microscope is a high power microscope that uses a compound lens system. Higher magnification is achieved by using two lenses rather than just a single magnifying lens. While the eyepieces and the objective lenses create high magnification, a condenser beneath the stage focuses the light directly into the sample. A compound microscope has multiple lenses: the objective lens (typically 4x, 10x, 40x or 100x) is compounded (multiplied) by the eyepiece lens (typically 10x) to obtain a high magnification of 40x, 100x, 400x and 1000x. The objective lenses of a compound microscope causes the orientation of the image of the specimen to be inverted compared to the orientation of the actual specimen which means that a specimen viewed through a compound microscope will look upside down and backwards compared to how the specimen is mounted on the slide.

Song H, Yan D, Wu W, Shen B, Feng X, Liu Y, Li L, Chu Q, Li M, Wang J, Tao R (2021) SRS suppression in multi-kW fiber lasers with a multiplexed CTFBG. Opt Express 29:20535–20544

Present address: Joint Advanced Technology Centre, Indian Institute of Technology Delhi, New Delhi, Delhi, 110016, India

Poulton CV, Yaacobi A, Cole DB, Byrd MJ, Raval M, Vermeulen D, Watts MR (2017) Coherent solid-state LIDAR with silicon photonic optical phased arrays. Opt Lett 42:4091–4094

Sumida DS, Jones DC, Rockwell DA (1994) An 8.2 J phase-conjugate solid-state laser coherently combining eight parallel amplifiers. IEEE J Quantum Electron 30:2617–2627

Dawson JW, Messerly MJ, Beach RJ, Shverdin MY, Stappaerts EA, Sridharan AK, Pax PH, Heebner JE, Siders CW, Barty CPJ (2008) Analysis of the scalability of diffraction-limited fiber lasers and amplifiers to high average power. Opt Express 16:13240–13266

Wang X, Wang X, Zhou P, Su R, Geng C, Li X, Xu X, Shu B (2012) 350-W coherent beam combining of fiber amplifiers with tilt-tip and phase-locking control. IEEE Photon Technol Lett 24:1781–1784

Carlson NW, Evans GA, Hammer JM, Lurie M, Palfrey SL, Dholakia A (1987) Phase-locked operation of a grating-surface-emitting diode laser array. Appl Phys Lett 50:1301–1303

Note: The microscope is now set to maximize resolution of  the  specimen.    If  you  adjust  the  condenser  height  to gain contrast or adjust light intensity you will sacrifice the resolution capability.  Use the aperture diaphragm and /or the illumination intensity to adjust contrast.

Geng C, Luo W, Tan Y, Liu H, Mu J, Li X (2013) Experimental demonstration of using divergence cost-function in SPGD algorithm for coherent beam combining with tip/tilt control. Opt Express 21:25045–25055

Panbiharwala Y, Harish AV, Feng Y, Venkitesh D, Nilsson J, Srinivasan B (2021) Stimulated Brillouin scattering mitigation using optimized phase modulation waveforms in high power narrow linewidth Yb-doped fiber amplifiers. Opt Express 29:17183–17200

Jabczyński JK, Gontar P (2021) Impact of atmospheric turbulence on coherent beam combining for laser weapon systems. Defence Technol 17:1160–1167

Shpakovych M, Maulion G, Kermene V, Boju A, Armand P, Desfarges-Berthelemot A, Barthélemy A (2021) Experimental phase control of a 100 laser beam array with quasi-reinforcement learning of a neural network in an error reduction loop. Opt Express 29:12307–12318

Charles Lailabai Linslal, Padmanabhan Ayyaswamy, Satyajit Maji, Mundakkolly Sureshbabu Sooraj, Awakash Dixit, Deepa Venkitesh & Balaji Srinivasan

Augst SJ, Ranka JK, Fan TY, Sanchez A (2007) Beam combining of ytterbium fiber amplifiers (Invited). J Opt Soc Am B 24:1707–1715

Kim J, Dupriez P, Codemard C, Nilsson J, Sahu JK (2006) Suppression of stimulated Raman scattering in a high power Yb-doped fiber amplifier using a W-type core with fundamental mode cut-off. Opt Express 14:5103–5113

Jiang M, Su R, Zhang Z, Ma Y, Wang X, Zhou P (2017) Coherent beam combining of fiber lasers using a CDMA-based single-frequency dithering technique. Appl Opt 56:4255–4260

Stage: the flat surface upon which the slide with your specimen is placed. Most microscopes have a stage finger assembly to hold the slide on the stage. The entire mechanism including the slide moves horizontally across the stationary stage (left/right and forward/back) using two stage adjustment knobs situated under the stage (variably on the left or right side, in front of the focusing knobs).

Klenke A, Müller M, Stark H, Tünnermann A, Limpert J (2018) Sequential phase locking scheme for a filled aperture intensity coherent combination of beam arrays. Opt Express 26:12072–12080

Poulton CV, Byrd MJ, Russo P, Timurdogan E, Khandaker M, Vermeulen D, Watts MR (2019) Long-range LiDAR and free-space data communication with high-performance optical phased arrays. IEEE J Sel Top Quantum Electron 25:1–8

Wang M, Liu L, Wang Z, Xi X, Xu X (2019) Mitigation of stimulated Raman scattering in kilowatt-level diode-pumped fiber amplifiers with chirped and tilted fiber Bragg gratings. High Power Laser Sci Eng 7

White JO, Young JT, Wei C, Hu J, Menyuk CR (2019) Seeding fiber amplifiers with piecewise parabolic phase modulation for high SBS thresholds and compact spectra. Opt Express 27:2962–2974

Base: the bottom of the microscope, which supports the entire instrument. The stage plate is located directly on the base surface upon which a specimen is placed. The stage can have a removable black or white tile (that can be removed and cleaned) or it will have a light that will transmit light through the specimen.

Axial Resolution: point-to-point resolving power in the plane parallel to the optical axis. It is usually defined at the shortest distance between two longitudinal points on the specimen plane that can still be distinguished as separate entities.

Towards ultimate high-power scaling:coherent beam combiningof fiber lasers

Stereo microscopes have low magnifications that can range from 2 to 100x depending on the microscope, and are designed for viewing whole objects like rocks, plants, flowers, and invertebrate organisms by reflecting light off the specimen, producing a 3-dimensional image. Sometimes there is a light located in the base of the microscope that will allow transmitted light.

Anderegg J, Brosnan S, Cheung E, Epp P, Hammons D, Komine H, Weber M, Wickham M (2006) Coherently coupled high-power fiber arrays. In: Proceedings of SPIE 6102, fiber lasers III: technology, systems, and applications, 61020U (23 February)

Microscope are used by the students in many lab exercises. Instructors also need to learn to use the instructor microscope with the Leica camera and required LAS EZ & Leica AirLab Icon Guide software which will allow them to project the microscope images in real time.

Hou T, Chang Q, Chang H, Liu W, Ma P, Su R, Ma Y, Zhou P (2020) Structuring orbital angular momentum beams by coherent laser array systems with tip-tilt optimization. Results Phys 19:103602

Tünnermann H, Shirakawa A (2019) Deep reinforcement learning for coherent beam combining applications. Opt Express 27:24223–24230

Kono Y, Takeoka M, Uto K, Uchida A, Kannari F (2000) A coherent all-solid-state laser array using the Talbot effect in a three-mirror cavity. IEEE J Quantum Electron 36:607–614

Harish AV, Nilsson J (2015) Optimization of phase modulation with arbitrary waveform generators for optical spectral control and suppression of stimulated Brillouin scattering. Opt Express 23:6988–6999

Coherent beam combiningppt

Fine adjustment or fine focusing knob: the smaller knob towards the back of the instrument that is used to make small adjustments in the height of the stage for final focusing on a specimen. It is the only focusing knob used with high power objectives.

Wang X, Ma Y, Zhou P, He B, Xiao H, Xue Y, Liu C, Li Z, Xu X, Zhou J, Liu Z, Zhao Y (2011) Coherent beam combining of 137W 2×2 fiber amplifier array. Opt Commun 284:2198–2201

Goodno GD, Asman CP, Anderegg J, Brosnan S, Cheung EC, Hammons D, Injeyan H, Komine H, Long WH, McClellan M, McNaught SJ, Redmond S, Simpson R, Sollee J, Weber M, Weiss SB, Wickham M (2007) Brightness-scaling potential of actively phase-locked solid-state laser arrays. IEEE J Sel Top Quantum Electron 13:460–472

Yu-Hao X, Bing H, Jun Z, Zhen L, Yuan-Yuan F, Yun-Feng Q, Chi L, Zhi-Jun Y, Hai-Bo Z, Qi-Hong L (2011) High power passive phase locking of four Yb-doped fiber amplifiers by an all-optical feedback loop. Chin Phys Lett 28:054212

The 100X objective lens is called an oil immersion lens because oil is placed between the lens and the microscope slide to increase resolution (i.e., the level of detail that can be observed in an image). Light bends when it passes from the glass slide to air because of differing refractive indices. A drop of immersion oil between the slide and lens eliminates this problem because the oil has the same refractive index as the glass slide. Never use the 100X  objective lens without oil and do not get oil on the 4X, 10X, or 40X lenses.

Shirakawa A, Saitou T, Sekiguchi T, Ueda K (2002) Coherent addition of fiber lasers by use of a fiber coupler. Opt Express 10:1167–1172

Fan X, Liu J, Liu J, Wu J (2010) Coherent combining of a seven-element hexagonal fiber array. Opt Laser Technol 42:274–279

Linslal, C.L., Ayyaswamy, P., Maji, S. et al. Challenges in coherent beam combining of high power fiber amplifiers: a review. ISSS J Micro Smart Syst 11, 277–293 (2022). https://doi.org/10.1007/s41683-022-00099-4

Li X, Xiao H, Dong X, Ma Y, Xu X (2011) Coherent beam combining of two slab laser amplifiers and second-harmonic phase locking based on a multi-dithering technique. Chin Phys Lett 28:094210

Flores A, Shay TM, Lu CA, Robin C, Pulford B, Sanchez AD, Hult DW, Rowland KB (2011) Coherent beam combining of fiber amplifiers in a kW regime. In CLEO:2011—laser applications to photonic applications, OSA technical digest (CD) (Optical Society of America)

Rothenberg JE, Thielen PA, Wickham M, Asman CP (2008) Suppression of stimulated Brillouin scattering in single-frequency multi-kilowatt fiber amplifiers. In: Proceedings of SPIE 6873, fiber lasers V: technology, systems, and applications, 68730O (22 February)

Depth of  Field: is determined by the distance from the nearest specimen plane in focus to that of the farthest plane also simultaneously in focus. The thickness of the optical section along the optical axis within which objects in the specimen plane are in focus. High-magnification objectives have a decreased depth of field. The reverse is true of low-magnification objectives Field of View:  the visible area seen through the microscope when the specimen is in focus. The greater the magnification the smaller the view. Focus:  a specimen is in focus at the desired magnification when the image seen through the ocular lens is sharp and clear.

Müller M, Aleshire C, Klenke A, Haddad E, Légaré F, Tünnermann A, Limpert J (2020) 10.4 kW coherently combined ultrafast fiber laser. Opt Lett 45:3083–3086

Cao J, Zhao X, Liu W, Gu H (2017) Performance analysis of a coherent free space optical communication system based on experiment. Opt Express 25:15299–15312

Ma Y, Wang X, Leng J, Xiao H, Dong X, Zhu J, Du W, Zhou P, Xu X, Si L, Liu Z, Zhao Y (2011a) Coherent beam combination of 1.08 kW fiber amplifier array using single frequency dithering technique. Opt Lett 36:951–953

Lateral Resolution: point-to-point resolving power in the plane perpendicular to the optical axis. It is usually defined as the shortest distance between two lateral points on the specimen plane that can still be distinguished as separate entities.

Qiu Y, Xie Y, Wang W, Liu W, Kuang L, Bai X, Hu M, Ho J (2019) Ultra-high-power and high-efficiency 905 nm pulsed laser for LiDAR. In: 2019 IEEE 4th optoelectronics global conference (OGC), pp 32–35

Coherent combining of light from multiple high power fiber amplifiers is a promising pathway to scaling the output power to hundreds of kiloWatts. In the last decade, substantial progress has been made in terms of scaling number of elements along with improvement in phase control techniques to achieve stable locking, resulting in tens of kiloWatts of output power. In this paper, we review the progress in coherent beam combining of fiber amplifiers in the master oscillator power amplifier configuration. We also discuss the challenges in power scaling as well as the current trends in the corresponding mitigation strategies. Specifically, the use of optimized phase modulation waveforms for mitigation of stimulated Brillouin scattering in high power amplifiers, scaling of the number of beam combining elements through deep-learning based phase control, and the use of micro-lens array for enhancing beam combination efficiency are discussed.

The authors would like to acknowledge funding support by DRDO Laser Science & Technology Centre (LASTEC) and Centre for High Energy Systems & Sciences (CHESS) through Contract for Acquisition of Research Services (CARS) projects, and MHRD/DRDO, Government of India through the Impacting Research Innovation and Technology scheme (IMPRINT/5375), as well as technical discussions with Drs. Anup Shah and Jagannath Nayak. The authors are thankful to Prof. Johan Nilsson and Dr. Yusuf Panbiharwala for the technical discussions.

Liu Z, Ma P, Su R, Tao R, Ma Y, Wang X, Zhou P (2017) High-power coherent beam polarization combination of fiber lasers: progress and prospect [Invited]. J Opt Soc Am B 34:A7–A14

Tünnermann H, Pöld JH, Neumann J, Kracht D, Willke B, Weßels P (2011) Beam quality and noise properties of coherently combined ytterbium doped single frequency fiber amplifiers. Opt Express 19:19600–19606

Thielen PA, Ho JG, Burchman DA, Goodno GD, Rothenberg JE, Wickham MG, Flores A, Lu CA, Pulford B, Robin C, Sanchez AD, Hult D, Rowland KB (2012) Two-dimensional diffractive coherent combining of 15 fiber amplifiers into a 600 W beam. Opt Lett 37:3741–3743

Augst SJ, Fan TY, Sanchez A (2004) Coherent beam combining and phase noise measurements of ytterbium fiber amplifiers. Opt Lett 29:474–476

Diopter: compensates for focusing differences between your eyes, it is very important this is set correctly, in order to prevent eye strain.

Prossotowicz M, Flamm D, Heimes A, Jansen F, Otto H, Budnicki A, Killi A, Morgner U (2021) Dynamic focus shaping with mixed-aperture coherent beam combining. Opt Lett 46:1660–1663

Jul 2, 2022 — Short for Cyan, Magenta, Yellow, and Key, CMYK is the four-color model used for printing standard colors. The image is an example of colors ...

Ma P, Chang H, Ma Y, Su R, Qi Y, Wu J, Li C, Long J, Lai W, Chang Q, Hou T, Zhou P, Zhou J (2021) 7.1 kW coherent beam combining system based on a seven-channel fiber amplifier array. Opt Laser Technol 140:107016

Vikram BS, Prakash R, Balaswamy V, Supradeepa VR (2021) Determination and analysis of line-shape induced enhancement of stimulated Brillouin scattering in noise broadened, narrow linewidth, high power fiber lasers. IEEE Photon J 13:1–12. https://doi.org/10.1109/JPHOT.2021.3067350

Illuminator or light source: the light source is usually built into the base of the microscope, and directs light through the condenser to the specimen.Alternatively, the light source may be separate, and be directed toward the condenser with a mirror. The intensity of the light can be adjusted using the rheostat (light) control knob. The microscope you are using has a rheostat on the front of the base and a switch on the left of the base.

Jin Y, Hassan A, Jiang Y (2016) Freeform microlens array homogenizer for excimer laser beam shaping. Opt Express 24:24846–24858

Labroille G, Denolle B, Jian P, Genevaux P, Treps N, Morizur J (2014) Efficient and mode selective spatial mode multiplexer based on multi-plane light conversion. Opt Express 22:15599–15607

The reduction of Airy disk radius produces an increase in resolution as objective numerical aperture increases. This interactive tutorial explores Airy disk ...

Lombard L, Canat G, Durecu A, Bourdon P (2014) Coherent beam combining performance in harsh environment. In: Proceedings of SPIE 8961, fiber lasers XI: technology, systems, and applications, 896107 (12 March)

Shay TM, Baker JT, Sanchez AD, Robin CA, Vergien CL, Zeringue C, Gallant D, Lu CA, Pulford B, Bronder TJ, Lucero A (2009) High-power phase locking of a fiber amplifier array. In: Proceedings of SPIE 7195, fiber lasers VI: technology, systems, and applications, 71951M (19 February)

Hou T, An Y, Chang Q, Ma P, Li J, Zhi D, Huang L, Su R, Wu J, Ma Y, Zhou P (2019) Deep-learning-based phase control method for tiled aperture coherent beam combining systems. High Power Laser Sci Eng 7:e59

Ocular lens or eyepiece: the secondary optical system that you look through. The ocular lens further magnifies (10x) the image and brings the light rays to a focal point. A binocular microscope has two ocular lenses and a monocular microscope has one ocular lens that sit on the adjustable binocular body. Binocular lenses can be adjusted to fit the distance between your eyes by gently pulling the oculars apart or by pushing them closer together.

Hansryd J, Dross F, Westlund M, Andrekson PA, Knudsen SN (2001) Increase of the SBS threshold in a short highly nonlinear fiber by applying a temperature distribution. J Light Technol 19:1691–1697

Apr 26, 2021 — Light can be polarised by passing it through a polarising filter. A polarising filter has all its molecules aligned in the same direction. As a ...

Objective lenses: the primary optical system which produces a magnified image of the specimen. There are typically four objective lenses attached to the nosepiece with the magnification of each objective is engraved on its side.

The resolving power of a microscope is dependent on the numerical apertures of the optical lenses and the wavelength of light used to examine the specimen. It is the smallest distance between two points (measured in microns) that can be seen with the microscope.  If two small objects close together can be seen clearly as two distinct objects, a microscope is said to have high resolving power.

Nov 13, 2015 — Eyepieces work in combination with microscope objectives to further magnify the intermediate image so that specimen details can be observed.

Fini JM, Mermelstein MD, Yan MF, Bise RT, Yablon AD, Wisk PW, Andrejco MJ (2006) Distributed suppression of stimulated Raman scattering in an Yb-doped filter-fiber amplifier. Opt Lett 31:2550–2552

2F 2.2mm POF Plastic Optical Fiber Cable · POF is made of low-cost materials. · Installation and associated assemblies are not expensive. · It is flexible and ...

Coherent beam combiningpdf

Montoya J, Hwang C, Martz D, Aleshire C, Fan TY, Ripin DJ (2017) Photonic lantern kW-class fiber amplifier. Opt Express 25:27543–27550

Ma Y, Zhou P, Wang X, Ma H, Xu X, Si L, Liu Z, Zhao Y (2011b) Active phase locking of fiber amplifiers using sine-cosine single-frequency dithering technique. Appl Opt 50:3330–3336

Coherent beam combiningcost

Richardson DJ, Nilsson J, Clarkson WA (2010) High power fiber lasers: current status and future perspectives [Invited]. J Opt Soc Am B 27:B63–B92

4Pack 8-Pin Waterproof DT Connector Male and Female Wire Connectors with 16AWG 105℃ 600V Wires and Heat Shrink Tubes, Applicable for Automotive Electrical ...

Shiner B (2013) The impact of fiber laser technology on the world wide material processing market. In: Proceedings of the CLEO, OSA, San Jose, CA, USA, p AF2J.1

Yu CX, Augst SJ, Redmond SM, Goldizen KC, Murphy DV, Sanchez A, Fan TY (2011) Coherent combining of a 4 kW, eight-element fiber amplifier array. Opt Lett 36:2686–2688

Illuminator or light source: the light source can be built into the base of the microscope, transmitting light through the specimen and/or the light source may be above the specimen as incident light. The lights can be turned on using rheostat (light) control knob on the front of the base.

Moyer RH, Valley M, Cimolino MC (1988) Beam combination through stimulated Brillouin scattering. J Opt Soc Am B 5:2473–2489

Jones DC, Turner AJ, Scott AM, Stone SM, Clark RG, Stace C, Stacey CD (2010) A multi-channel phase locked fibre bundle laser. In: Proceedings of SPIE 7580, fiber lasers VII: technology, systems, and applications, 75801V (17 February)

Köhler illumination is the alignment of the image-forming light path and the illumination light path of the microscope. In this process the con-denser is centered and focused, thereby providing an evenly illuminated field of view and more importantly maximum resolution of the specimen

Magnification is the process of enlarging the apparent size, not physical size, of something. In microscopy, it is the ratio between the size of an image produced by the microscope and its actual size. Microscopes magnify thin specimens mounted on microscope slides. They are ideal for observing unicellular or very small organisms, cells, and cell structures. We will use the compound and dissecting microscopes many times over the course of the semester. It is important to familiarize yourself with microscope use.

Redmond SM, Ripin DJ, Yu CX, Augst SJ, Fan TY, Thielen PA, Rothenberg JE, Goodno GD (2012) Diffractive coherent combining of a 2.5 kW fiber laser array into a 1.9 kW Gaussian beam. Opt Lett 37:2832–2834

Chang H, Chang Q, Xi J, Hou T, Su R, Ma P, Wu J, Li C, Jiang M, Ma Y, Zhou P (2020) First experimental demonstration of coherent beam combining of more than 100 beams. Photon Res 8:1943–1948

Spectral vscoherent beam combining

Hu Q, Zhao X, Tian X, Li H, Wang M, Wang Z, Xu X (2022) Raman suppression in 5 kW fiber amplifier using long period fiber grating fabricated by CO2 laser. Opt Laser Technol 145:107484

Baumeister T, Brunton SL, Kutz JN (2018) Deep learning and model predictive control for self-tuning mode-locked lasers. J Opt Soc Am B 35:617–626

Bruesselbach H, Wang S, Minden M, Jones DC, Mangir M (2005b) Power-scalable phase-compensating fiber-array transceiver for laser communications through the atmosphere. J Opt Soc Am B 22:347–353

Prossotowicz M, Heimes A, Flamm D, Jansen F, Otto H, Budnicki A, Killi A, Morgner U (2020) Coherent beam combining with micro-lens arrays. Opt Lett 45:6728–6731

Cheung EC, Ho JG, Goodno GD, Rice RR, Rothenberg J, Thielen P, Weber M, Wickham M (2008) Diffractive-optics-based beam combination of a phase-locked fiber laser array. Opt Lett 33:354–356

Ayyaswamy P, Linslal CL, Dixit A, Venkitesh D, Srinivasan B (2021) Data-driven modeling of phase noise sources in coherent beam combining. In: Laser applications conference, OSA laser congress

Huo Y, Cheo PK, King GG (2004) Fundamental mode operation of a 19-core phase-locked Yb-doped fiber amplifier. Opt Express 12:6230–6239

Billaud A, Gomez F, Allioux D, Laurenchet N, Jian P, Pinel O, Labroille G (2020) Optimal coherent beam combining based on Multi-Plane Light Conversion for high throughput optical feeder links (conference presentation). In: Proceedings of SPIE 11272,free-space laser communications XXXII

Anderegg J, Brosnan SJ, Weber ME, Komine H, Wickham MG (2003) 8-W coherently phased 4-element fiber array. In; Proceedings of SPIE 4974, advances in fiber lasers (3 July)

Zhi D, Zhang Z, Ma Y, Wang X, Chen Z, Wu W, Zhou P, Si L (2017) Realization of large energy proportion in the central lobe by coherent beam combination based on conformal projection system. Sci Rep 7:2199

Vasilyev A, Petersen E, Satyan N, Rakuljic G, Yariv A, White JO (2013) Coherent Power Combining of Chirped-Seed Erbium-Doped Fiber Amplifiers. IEEE Photon Technol Lett 25:1616–1618

Zhou P, Liu Z, Wang X, Ma Y, Ma H, Xu X, Guo S (2009) Coherent beam combining of fiber amplifiers using stochastic parallel gradient descent algorithm and its application. IEEE J Sel Top Quantum Electron 15:248–256

Flores A, Dajani I, Holten RH, Ehrenreich T, Anderson BT (2016) Multi-kilowatt diffractive coherent combining of pseudorandom-modulated fiber amplifiers. Opt Eng 55(9):096101

Jauregui C, Eidam T, Limpert J, Tünnermann A (2011a) Impact of modal interference on the beam quality of high-power fiber amplifiers. Opt Express 19:3258–3271

Tünnermann H, Shirakawa A (2018) Reinforcement learning for coherent beam combining. In: 2018 conference on lasers and electro-optics Pacific Rim (CLEO-PR), pp 1–2

Stiles E (2009) New developments in IPG fiber laser technology. In: Proceedings of the 5th international workshop on fiber lasers

Coarse adjustment or coarse focusing knob: the large knob towards the back of the instrument that is used to significantly raise or lower the stage, when you first focus on a specimen at low power. It is never used when high power objectives are in place.

Loftus TH, Thomas AM, Norsen M, Minelly JD, Jones P, Honea E, Shakir SA, Hendow S, Culver W, Nelson B, Fitelson M (2008) Four-channel, high power, passively phase locked fiber array. In Advanced solid-state photonics, OSA technical digest series (CD) (Optical Society of America)

Zhou P, Xiao H, Leng J, Xu J, Chen Z, Zhang H, Liu Z (2017b) High-power fiber lasers based on tandem pumping. J Opt Soc Am B 34:A29–A36

Ricklin JC, Davidson FM (2002) Atmospheric turbulence effects on a partially coherent Gaussian beam: implications for free-space laser communication. J Opt Soc Am A 19:1794–1802

Diffraction Grating Film is an advanced optical component crafted for a variety of optical uses, especially in spectroscopy and laser tools. It is a precise ...

Honea E, Afzal RS, Savage-Leuchs M, Henrie J, Brar K, Kurz N, Jander D, Gitkind N, Hu D, Robin C, Jones AM, Kasinadhuni R, Humphreys R (2016) Advances in fiber laser spectral beam combining for power scaling. In: Proceedings ’components and packaging for laser systems II’, vol 9730

Liu Y, Lv Z, Dong Y, Li Q (2009) Research on stimulated Brillouin scattering suppression based on multi-frequency phase modulation. Chin Opt Lett 7:29–31

Ng AY, Coates A, Diel M, Ganapathi V, Schulte J, Tse B, Berger E, Liang E (2006) Autonomous inverted helicopter flight via reinforcement learning. In Experimental robotics IX. Springer, Berlin, Heidelberg, pp 363–372

Gamma Draconis is the brightest star in Draco. It has an apparent magnitude of 2.3617 and is 154.3 light years distant from the solar system. It is sometimes ...

Ma Y, Liu Z, Zhou P et al (2009) Coherent beam combination of three fiber amplifiers with multi-dithering technique. Chin Phys Lett 26:44204

Goodno GD, Shih C, Rothenberg JE (2010b) Perturbative analysis of coherent combining efficiency with mismatched lasers. Opt Express 18:25403–25414

Bruesselbach H, Jones DC, Mangir MS, Minden M, Rogers JL (2005a) Self-organized coherence in fiber laser arrays. Opt Lett 30:1339–1341

Dixit A, Sooraj MS, Linslal CL, Padmanabhan A, Venkitesh D, Srinivasan B (2021) Experimental validation of free-space coherent beam combining simulations for filled aperture configuration. In: Conference on lasers and electro-optics (CLEO 2021), OSA technical digest (Optical Society of America)

Microscopes  must  be  calibrated  so  accurate measurements can be made. To calibrate a microscope  both  an  ocular  and  a  stage  micrometer are used.

Satyan N, Vasilyev A, Rakuljic G, White JO, Yariv A (2012) Phase-locking and coherent power combining of broadband linearly chirped optical waves. Opt Express 20:25213–25227

Corcoran CJ, Rediker RH (1991) Operation of five individual diode lasers as a coherent ensemble by fiber coupling into an external cavity. Appl Phys Lett 59:759–761

McNaught SJ, Asman CP, Injeyan H, Jankevics A, Johnson AMF, Jones GC, Komine H, Machan J, Marmo J, McClellan M, Simpson R, Sollee J, Valley MM, Weber M, Weiss SB (2009) 100-kW coherently combined Nd:YAG MOPA laser array. In Frontiers in optics 2009/laser science XXV/fall

Beyer E (2008) High power laser materials processing—new developments and trends. In: Pacific international conference on applications of lasers and optics 2008, pp 5–9

Focusing knob: the knob that allows you to focus on the object at each magnification by moving the stereo head up or down.