Info
Info
News Article

US Researchers Develop Room Temperature Polariton Laser

Device  could be future optical replacement for on-chip wires

Scientists from the University of Michigan and Intel Corporation in the US have demonstrated what appears to be the first electrically powered, room-temperature polariton laser. The device, based on a GaN-based microcavity diode, could advance efforts to replace on-chip wire connections with lasers, leading to smaller and more powerful electronics, say the researchers.

A polariton is a quasiparticle that results from a coupling between a photon and an electron-hole pair (an "exciton") in a semiconductor material. In 1996, researchers realised that-under certain conditions-polaritons will condense into a single quantum state, from which they will spontaneously emit coherent, monochromatic light. In contrast to stimulated lasing, the polariton emitters do not need to be constantly pumped up into excited states (so-called population inversion). As a consequence, polariton lasers begin lasing at a relatively low threshold power.

Experimental realisations of polariton lasers have so far required either low temperatures or a pump laser to create the initial polaritons. Described in the journal Physical Review Letters, the room temperature polariton laser produced a beam of UV laser light at a threshold current density of 169 A/cm2, which is almost a factor of 100 less than for conventional GaN-based lasers. 

The device consists of a thin strip of gallium nitride, sandwiched between stacks of metal oxide mirrors. (In the diagram above, the mirrors are represented by the grey bars. The yellow is the electrode through which the researchers stimulate the laser. The purple is the gallium nitride semiconductor). When electric current enters such a microcavity, it can generate polaritons. But unlike previous designs in which electricity passed through or around the high-resistance mirrors, the team injects current orthogonally to the microcavity's emitting direction, thus avoiding overheating the device and destroying the lasing. 

"˜Room Temperature Electrically Injected Polariton Laser' by P Bhattacharya et al, Phys. Rev. Lett. 112, 236802 (2014)



AngelTech Live III: Join us on 12 April 2021!

AngelTech Live III will be broadcast on 12 April 2021, 10am BST, rebroadcast on 14 April (10am CTT) and 16 April (10am PST) and will feature online versions of the market-leading physical events: CS International and PIC International PLUS a brand new Silicon Semiconductor International Track!

Thanks to the great diversity of the semiconductor industry, we are always chasing new markets and developing a range of exciting technologies.

2021 is no different. Over the last few months interest in deep-UV LEDs has rocketed, due to its capability to disinfect and sanitise areas and combat Covid-19. We shall consider a roadmap for this device, along with technologies for boosting its output.

We shall also look at microLEDs, a display with many wonderful attributes, identifying processes for handling the mass transfer of tiny emitters that hold the key to commercialisation of this technology.

We shall also discuss electrification of transportation, underpinned by wide bandgap power electronics and supported by blue lasers that are ideal for processing copper.

Additional areas we will cover include the development of GaN ICs, to improve the reach of power electronics; the great strides that have been made with gallium oxide; and a look at new materials, such as cubic GaN and AlScN.

Having attracted 1500 delegates over the last 2 online summits, the 3rd event promises to be even bigger and better – with 3 interactive sessions over 1 day and will once again prove to be a key event across the semiconductor and photonic integrated circuits calendar.

So make sure you sign up today and discover the latest cutting edge developments across the compound semiconductor and integrated photonics value chain.

REGISTER FOR FREE

VIEW SESSIONS

Info
×
Search the news archive

To close this popup you can press escape or click the close icon.
×
Logo
×
Register - Step 1

You may choose to subscribe to the Compound Semiconductor Magazine, the Compound Semiconductor Newsletter, or both. You may also request additional information if required, before submitting your application.


Please subscribe me to:

 

You chose the industry type of "Other"

Please enter the industry that you work in:
Please enter the industry that you work in:
 
X
Info
X
Info
{taasPodcastNotification}
Live Event