Tag: IISC Classical Musical Group

NATIONAL / KARNATAKA: SCIENCE & TECHNOLOGY: IISc designs device to make infrared light visible, with diverse applications in defence and optical communications

Researchers at the Indian Institute of Science (IISc) have fabricated a device to increase or up-convert the frequency of short infrared light to the visible range. This up-conversion of light has diverse applications, especially in defence and optical communications, said IISc.

“The human eye can only see light at certain frequencies (called the visible spectrum), the lowest of which constitutes red light. Infrared light, which we can’t see, has an even lower frequency than red light. IISc researchers have now fabricated a device to increase or up-convert the frequency of short infrared light to the visible range,” IISc said.

2D material used

The institute added that in a first, the IISc team used a 2D material to design what they call a non-linear optical mirror stack to achieve this up-conversion, combined with widefield imaging capability. The stack consists of multilayered gallium selenide fixed to the top of a gold reflective surface, with a silicon dioxide layer sandwiched in between.

It said that traditional infrared imaging uses exotic low-energy bandgap semiconductors or micro-bolometer arrays, which usually pick up heat or absorption signatures from the object being studied.

However, existing infrared sensors are bulky and not very efficient. They are also export-restricted because of their utility in defence. There is, therefore, a critical need to develop indigenous and efficient devices.

The method used by the IISc team involves feeding an input infrared signal along with a pump beam onto the mirror stack. The nonlinear optical properties of the material constituting the stack result in a mixing of the frequencies, leading to an output beam of increased (up-converted) frequency, but with the rest of the properties intact. Using this method, they were able to up-convert infrared light of a wavelength of around 1,550 nm to 622 nm visible light. The output light wave can be detected using traditional silicon-based cameras.

Going forward, the researchers plan to extend their work to up-convert light of longer wavelengths. They are also trying to improve the efficiency of the device by exploring other stack geometries.

Worldwide interest

“There is a lot of interest worldwide in doing infrared imaging without using infrared sensors. Our work could be a game-changer for those applications,” said Varun Raghunathan, associate professor, Department of Electrical Communication Engineering.

source/content: thehindu.com (headline edited)

KARNATAKA: ARTS & CRAFTS / MUSIC: Indian Institute of Science’s (IISc) Classical Music Group ‘Geetanjali’ is 150 members strong and to perform ‘The Myriad Colours of Indian Music’

The classical music wing was started by Geeta in 2015. She is a Hindustani singer. Her husband is a faculty member at IISc. She holds music classes at her home, which is located on the IISc campus.

Research scholars and faculty members of the Indian Institute of Science (IISc) will put up a 90-minute music show on their campus next week.

The show is called ‘The myriad colours of Indian music’ and will be held on the sidelines of ‘The International Conference on Fracture Mechanics of Concrete and Concrete Structures’. “A lot of foreign delegates come to IISc for conferences. We want to give them a glimpse of Indian music,” says Geeta Ananth, who has conceptualised the show.

The performance will be a mix of Hindustani and Carnatic music, Kannada bhavageethe, folk songs, bhajans, ghazals and other genres. A folk dance is also scheduled.

These research scholars and faculty members are part of Geetanjali, the classical music wing of the institutes’s Music Club.

The classical music wing was started by Geeta in 2015. She is a Hindustani singer. Her husband is a faculty member at IISc. She holds music classes at her home, which is located on the IISc campus.

Explaining why she started Geetanjali, she says, “There was no forum to promote classical music and showcase talent on the campus.”

The group has more than 150 members now and the music classes have become a stress-buster for students, she shares.

The group will perform alongside professional artistes like Raghavendra Nakod, Niranjan Hegde and Surya Upadhyaya.

 ‘The myriad colours of Indian music’ on September 11, 6.30 pm, at J N Tata Auditorium, C V Raman Road. Entry free.

source/content: deccan herald.com (headline edited)