New ultrathin lens to make mobiles as thin as credit cards

The new lens is flat, distortion-free and so
small that more than 1,500 would fit across the width of
a human hair.

Washington: Scientists are developing a new ultrathin lens which could lead to smart phones as thin as a credit card.

The new lens is flat, distortion-free and so small that more than 1,500 would fit across the width of a human hair - capable in the future of replacing lenses in applications ranging from cell phones to cameras to fiber-optic communication systems.

In a study published in journal Nano Letters, Federico Capasso and colleagues explained that the lenses used to focus light in eyeglasses, microscopes and other products use the same basic technology dating to the late 1200s, when spectacle lenses were introduced in Europe.

Existing lenses are not thin or flat enough to remove distortions, such as spherical aberration, astigmatism and coma, which prevent the creation of a sharp image.

Correction of those distortions requires complex solutions, such as multiple lenses that increase weight and take up space. To overcome these challenges, the scientists sought to develop a new superthin, flat lens.

Although the new lens is ultra-thin, it has a resolving power that actually approaches the theoretical limits set by the laws of optics.

The lens surface is patterned with tiny metallic stripes which bend light differently as one moves away from the centre, causing the beam to sharply focus without distorting the images.

The current version of the lens works at a specific design wavelength, but the scientists say it can be redesigned for use with broad-band light.

BSNL launches landline phones with video call facility

NEW DELHI: State-run BSNL, in partnership with SIS Infosystems, today launched telephones with video calling facility which will primarily be used to set up public Video Call Offices by replacing many of the PCOs. 

"We will convert existing Public Call Offices (PCOs) to VCOs with these phones. People will be able to make voice calls to any phone and video calls to any other IP (internet based) phone,"BSNL Chairman and Managing Director R K Upadhyay told reporters here. 

He said that most of the revenue of BSNL comes from landline phones and this new services is one of the initiative to increase company's revenue.

BSNL will charge Rs 3 for 45 second video call made from VCO which will include 30 per cent commission for the franchise owner.

"There will be no need to use computers for making video calls for user of these video phones," Upadhyay said.

BSNL's Senior General Manager for Broadband, A K Jain said that around 770 PCOs have confirmed to shift their business to VCOs and the target is to have 10,000 VCOs set-up across the country.

The service was inaugurated by Advisor to Prime Minister Sam Pitroda who stressed on the use of video phones to reach rural masses.

"It will bridge the gap between urban and rural India. This will be a platform for growth as this network can be used for purposes like job interview, tele-medicine, tele-education and host of other services," Pitroda said.

BSNL will provide various categories of VCO franchisees based on the services that a franchisee owners wants to provide.

SIS officials said that people looking for franchisee will have to pay for VCO devices which starts from Rs 25,000 and will have to sign an agreement for the business.

An official said VCOs having medical devices attached to it for remote diagnosis of a patient will also be made available. Many other services will be launched shortly for which prices will differ.