Memory Cell for Data Storage – II
Patent 10004/TUB

This memory cell serves as an optoelectronic device for data storage and can be used, among other things, for quantum cryptography and data transmission as used in the communications industry.

  1. Large single photon yield and bit rate
  2. Large Purcell and quality factors
  3. Compensation of temperature fluctuation
Possible Applications

The invention is fundamental for the mass production of inexpensive single photon emitters based on standard semiconductor technologies for quantum cryptography.


For secure data transmission quantum cryptography will be used. Inexpensive emitters of single photons are of essence for mass applications. Emitting more than one photon at a time leads to photon number splitting (PNS) which allows eavesdropping.

Technical Description

The presently only known cost effective approach potentially allowing room temperature operation is to use an LED with Bragg reflectors and an oxide aperture, well known from VCSEL technology, to emit single photons from single quantum dots (QD) placed below or above, but in the center of the aperture. Including a piezoelectric actuator allows the tuning of cavity by external stress and making the emission energy tunable. The lateral and vertical expansion of the actuator with applied voltage controls the cavity modes and QD emission energy. This allows tuning of the Bragg mirror transmission with the QD emission energy.
The yield of single photons is also increased together with an increase of the possible bit rate to the Gbit/s range.

Contact Us

Ina Krüger

Technology Transfer Manager

+49 (0)30 314-75916

Technology Readiness Level

Technology validated in lab

Property Rights

approved: US, DE, FR, GB

Patent Holder

Technische Universität Berlin

Possible Cooperation
  • R&D Cooperation
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  • Licensing