BOSTON – Using semi­con­ductor nan­otech­nology, Srinivas Sridhar, Ph.D., Dis­tin­guished Pro­fessor and Chair of Physics at North­eastern Uni­ver­sity, and his team of researchers from the university’s Elec­tronic Mate­rials Research Insti­tute have cre­ated a new microlens that focuses infrared light at telecom­mu­ni­ca­tion fre­quen­cies. The focusing power of this microlens sets a world record for one of the shortest focal lengths ever achieved, focusing the infrared beam to a spot just 12 microm­e­ters away from the sur­face. This rep­re­sents an advance in light imaging tech­nology and has the poten­tial to lead to inno­va­tions in how cur­rent per­sonal elec­tronic devices are manufactured.

The two-​​dimensional meta-​​material microlens, which uses the neg­a­tive refrac­tive index, was cre­ated by nano-​​engineering a photonic-​​crystal sub­strate into a multi-​​layered semi­con­ducting wafer. The microlens focused infrared light to a loca­tion just 12 microm­e­ters away from the lens sur­face – one of the shortest focal lengths recorded – at the limit of dif­frac­tion laws. In addi­tion, the loca­tion of the focused light image was very sharp with little blurring.

In order to go to the next level and create more effi­cient elec­tronics, such as dig­ital cam­eras, we need to explore ways to make things smaller,” said Sridhar. “This research shows that it is pos­sible to create smaller, ultra-​​compact infrared optical com­po­nents that can be inte­grated into existing semi­con­ductor tech­nolo­gies while not sac­ri­ficing image quality.”

In addi­tion to Sridhar, the team of researches involved with this project includes Bernard Didier F. Casse, Ph.D., Wentao Lu, Ph.D., and Yongjiang Huang, all from Northeastern’s Physics depart­ment. The report was pub­lished in the August 7 edi­tion of the journal Applied Physics Let­ters. This work was also sup­ported by the Air Force Research Lab­o­ra­to­ries and the National Sci­ence Foundation.

Light imaging tech­nology is a cru­cial com­po­nent to the field of opto­elec­tronics, which uses light instead of elec­trons for car­rying infor­ma­tion, and rep­re­sents the next gen­er­a­tion of com­bined optical and elec­tronic plat­forms essen­tial for future com­puters,” added Sridhar.

For more infor­ma­tion about Pro­fessor Sridhar’s research, please con­tact Jenny Eriksen at (617) 373‑2802 or via email at j.​eriksen@​neu.​edu.

About North­eastern University

Founded in 1898, North­eastern Uni­ver­sity is a pri­vate research uni­ver­sity located in the heart of Boston. North­eastern is a leader in inter­dis­ci­pli­nary research, urban engage­ment, and the inte­gra­tion of class­room learning with real-​​world expe­ri­ence. The university’s dis­tinc­tive coop­er­a­tive edu­ca­tion pro­gram, where stu­dents alter­nate semes­ters of full-​​time study with semes­ters of paid work in fields rel­e­vant to their pro­fes­sional inter­ests and major, is one of the largest and most inno­v­a­tive in the world. The Uni­ver­sity offers a com­pre­hen­sive range of under­grad­uate and grad­uate pro­grams leading to degrees through the doc­torate in six under­grad­uate col­leges, eight grad­uate schools, and two part-​​time divi­sions. For more infor­ma­tion, please visit www​.north​eastern​.edu.