Experimental demonstration of underwater optical wireless power transfer using a laser diode

Abstract

We experimentally demonstrate an underwater optical wireless power transfer (OWPT) using a laser diode (LD) as a power transmitter. We investigate the characteristics of a solar cell and a photodiode (PD) as a power receiver. We optimize the LD, the PD, and the solar cell to achieve the maximum transfer efficiency. The maximum transfer efficiency of the back-to-back OWPT is measured as 4.3% with the PD receiver. Subsequently, we demonstrate the OWPT in tap and sea water. Our result shows an attenuation of 3 dB/m in sea water. OCIS codes: 010.3310, 010.

Wireless Power Transfer: Systems, Circuits, Standards, and Use Cases

“…With corrections, efficiencies of 40–60% are possible, according to [ 61 ]. An underwater LPT setup was tested [ 62 ], resulting in an overall efficiency of 4%. The laser output power corresponded with 50 m .…”

Wireless Power Transfer for Unmanned Underwater Vehicles: Technologies, Challenges and Applications

“…Regarding underwater optical link transmission, very few experiments can be found in the literature [56][57][58]. All of these could achieve power transfers in the mW range, with a power transfer efficiency below 20% for distances over 1 m. Regarding data transfer, in [57], the authors achieved data rates up to 60 Mbps at the receiver side, at a distance of 2.3 m from the emitter.…”

Optical Wireless Power Transmission under Deep Seawater Using GaInP Solar Cells

“…ηop of the 532 nm laser was the highest; however, the ηop of the 635 nm laser in summer was the highest due to the increase in the proliferation of phytoplankton because of the temperature rise in seawater and the increased sunshine hours. As explained above, the light reaching rate varies depending on location [8][9][10][11][12][13][14], season [24], and depth of seawater collection [12]. In this study, deep seawater and tap water were prepared to reproduce the seafloor exploration environment.…”

“…However, as shown in Figure 1, the attenuation rate of the 532 nm green laser was the lowest, although there were some differences depending on the seawater sampling area [22,23]. With the recent confirmation of the existence of marine resources on the seafloor, the OWPT system has also been researched in anticipation of under water and seawater exploration [10][11][12][13]. Miyamoto et al reported that a GaAs solar cell was irradiated with 450 nm laser light at 6 W through a fly-eye lens in a 90 cm long water tank, and the power was converted to 0.755 W. [10].…”

“…Miyamoto et al reported that a GaAs solar cell was irradiated with 450 nm laser light at 6 W through a fly-eye lens in a 90 cm long water tank, and the power was converted to 0.755 W. [10]. Kim reported an attenuation of 3.0 dB/m in OWPT in seawater and showed that power can be transmitted wirelessly with a transmission efficiency of 2% up to an underwater optical path length of 1 m [11]. Putra and Maruyama calculated a total system efficiency (including the laser efficiency) of 13.1% at a wavelength 570 nm for a 1 m depth of water, 10.2% at 480 nm for a 10 m depth of water, and 7.3% and 5.5% at around 400 nm wavelength for 50 m and 100 m depths of water [12].…”