VCSEL Industry. Babu Dayal Padullaparthi

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СКАЧАТЬ the Joint Strike Fighter (JSF) program. Three centers for optoelectronics were started in universities. Honeywell, Motorola, and HP were the primary companies working on the programs. More details can be found in the wiki page:

       https://en.wikipedia.org/wiki/Vertical‐cavity_surface‐emitting_laser.

      Areas of emphasis in Stage II include mass production technology [40], threshold current reduction[39–42], transverse mode control, oxidation [43, 44], polarization control, initial tunable VCSELs [45], MEMS elements [46], 2D arrays [47], high‐speed and high‐power VCSELs, InP‐based device with continuous operation [48] and quantum wells VCSELs, and so on. This was a golden period in the VCSEL journey to mass production, and many technical and manufacturing advances contributed to the foundation of VCSEL technology.

      1.3.3 Stage III: Extension of Applications and Initial Commercialization

      Stage‐III of VCSEL development started in 1999, shown in Figure 1.12, as we entered a new information and technology era in 2000. The third stage (1999–2010) brought on new development of wavelengths, single mode, VCSEL arrays, volume manufacturing driven by Internet traffic demand, autofocus, and so forth, and the focus has shifted to commercial efforts. Why did 1310–1550 nm VCSELs not become widely adopted? That was primarily due to the technical difficulty of making mirrors and overcoming optical loss in materials.

In 2000 one of the authors (Iga) wrote a VCSEL review paper [49] and in the same special issue, DARPA managers Elias Towe, Robert F. Leheny, and Andrew Yang wrote the following about VCSEL in their review paper [50]: “Its size, manufacturability, and potential ease of heterogeneous integration of electronics promise a range of applications that have yet to be explored.” This was the time when DARPA invested considerable human and monetary resources in the R&D of VCSEL, in particular the massive integration of VCSELs, detectors, micro‐optics and driving electronics for free‐space optical interconnects and all optical switching. However, practical and commercial free‐space interconnect and all optical switching did not really pick up during the subsequent years. This investment nonetheless continued to drive VCSEL innovations such as high‐power VCSEL arrays, high‐contrast gratings, athermal VCSELs, coupled cavity VCSELs, VCSELs‐based slow light waveguide devices, multi‐wavelength VCSELs/WDM [51], quantum dot VCSELs, high‐bandwidth VCSELs (>20 GHz), and so forth.

      VCSELs are currently applied in various optical systems, such as optical networks, parallel optical interconnects, laser printers, computer mice, and so on. The three critical application areas that provided the commercial impetus for continued VCSEL expansion were high‐speed data connectivity, computer mice, and laser printing.

      1.3.3.1 LAN for Internet

      A first large market for VCSELs with large‐scale production had begun in 1995 [40]. Around 1999, the Internet spread rapidly worldwide. The dramatic growth of data centers created communication networks that support the Internet, including long‐distance optical fiber networks and local area networks (LANs). Metaphorically, the artery of the blood vessel is the long‐distance line, and the LAN is a capillary. VCSEL was adopted as a light source for LANs operating at 1 Gbit/s and running Fiber Channel and Ethernet protocols.

      The protocols were further standardized (10G; IEEE802.3ae in 2002, 100G; IEEE802.3ba in 2011) for the optical fiber communication that constitutes the LAN of the Internet. In 2020, high speed VCSELs and the pulse amplitude modulation (PAM) scheme have been developed for 400 Gbit/s high‐speed Ethernet. Information flows through the capillaries of companies and universities. Details on VCSELs in data communications will be covered in Chapter 4.

      In addition to applications in data centers owned and operated by IT companies, national organizations and universities began to include optical interconnects in computing architectures. For the supercomputer TSUBAME 3.0 by Tokyo Institute of Technology more than 16 000 VCSELs were included in the system. More than 300 000 VCSELs are used in IBM’s top supercomputer. In the world’s fastest (2019 and 2020) supercomputer Fugaku of RIKEN of Japan, it was reported that the numbers of VCSEL chips used was 640 000.

       https://www.r‐ccs.riken.jp/en/fugaku/project/outline.

       https://www.fujitsu.com/downloads/SUPER/primehpc‐fx1000‐hard‐en.pdf.

      1.3.3.2 Computer Mouse

      A computer is one way to access the Internet, and a computer mouse is useful for operating a computer. Since around the year 2000, VCSELs have also been applied to computer mice by Hewlett‐Packard; this represented the first high volume use of VCSELs in a consumer market. The use of VCSELs in consumer electronics may be comparable to the development of electronic devices such as LSIs and semiconductor memories. VCSELs used in computer mice will be further discussed in Chapter 8.

      1.3.3.3 Laser Printers

      VCSEL arrays were introduced into laser printers in 2001 by companies such as Fuji Xerox, Ricoh, and Canon/Sony. Since then, VCSELs have largely replaced edge‐emitting lasers and LEDs in printers. The aforementioned companies have about 80% market share of integrated laser printers in the world. VCSELs in laser printing will be further discussed in Chapter 8.

      1.3.4 Stage IV: Spread of VCSEL Photonics

      In the fourth stage of VCSEL history, from 2010 to 2020, the true scaling of VCSEL production has been realized. In data communication, highly reliable 850 nm VCSELs are made using InGaAs quantum wells with 3 dB bandwidths exceeding 25 GHz and operated above 70 Gb/s NRZ. New modulation (PAM‐4) standards are made for higher speeds to meet the continued network demand. This is also supported by development of short wavelength WDM VCSELs (in the 850–980 nm band).

      In the optical sensing area, high‐power 940 nm VCSELs arrays have been made with optimized designs with power conversion efficiency > 50%, slope efficiency = 1.0 W/A, and with new trends of using multi‐tunnel junctions that offer a power conversion efficiency > 60%, slope efficiency = 3.0 W/A, with power densities of 1 kW/mm². This facilitated the use of VCSEL arrays in consumer devices (mobile/smart phones/smart homes), infrastructure and transport applications incorporating LiDAR, surveillance and night vision products, robots, drones, IoT, and so on. Further applications include multi‐mode VCSEL arrays in LiDARs at 905 nm, 850 nm, and 1060 nm; large‐scale 940 nm arrays in industrial heating systems. On the other hand, single‐mode VCSELs are being applied to optical coherence tomography (1060 nm) and atomic clocks. Details and references can be found in related chapters.

      The multi‐function ability of VCSELs further expanded manufacturing bases across the world with investments prompting high market demands never seen before. This also triggered high‐volume manufacturing from 4" (100 mm) to 6" (150 mm) for optical sensor products. All these items will be discussed in Chapters 3–9.

      1.3.5 СКАЧАТЬ