Optical RAM row access using WDM-enabled all-passive row/column decoders

Sotirios Papaioannou, Theoni Alexoudi, George T. Kanellos, Amalia Miliou, Nikos Pleros

Research output: Chapter in Book/Report/Conference proceedingConference Contribution (Conference Proceeding)


Towards achieving a functional RAM organization that reaps the advantages offered by optical technology, a complete set of optical peripheral modules, namely the Row (RD) and Column Decoder (CD) units, is required. In this perspective, we demonstrate an all-passive 2×4 optical RAM RD with row access operation and subsequent all-passive column decoding to control the access of WDM-formatted words in optical RAM rows. The 2×4 RD exploits a WDM-formatted 2-bit-long memory WordLine address along with its complementary value, all of them encoded on four different wavelengths and broadcasted to all RAM rows. The RD relies on an all-passive wavelength-selective filtering matrix (λ-matrix) that ensures a logical '0' output only at the selected RAM row. Subsequently, the RD output of each row drives the respective SOA-MZI-based Row Access Gate (AG) to grant/block the entry of the incoming data words to the whole memory row. In case of a selected row, the data word exits the row AG and enters the respective CD that relies on an allpassive wavelength-selective Arrayed Waveguide Grating (AWG) for decoding the word bits into their individual columns. Both RD and CD procedures are carried out without requiring any active devices, assuming that the memory address and data word bits as well as their inverted values will be available in their optical form by the CPU interface. Proof-of-concept experimental verification exploiting cascaded pairs of AWGs as the λ-matrix is demonstrated at 10Gb/s, providing error-free operation with a peak power penalty lower than 0.2dB for all optical word channels.

Original languageEnglish
Title of host publicationOptical Components and Materials XI
PublisherSociety of Photo-Optical Instrumentation Engineers (SPIE)
ISBN (Print)9780819498953
Publication statusPublished - 1 Jan 2014
EventOptical Components and Materials XI - San Francisco, CA, United States
Duration: 3 Feb 20145 Feb 2014


ConferenceOptical Components and Materials XI
Country/TerritoryUnited States
CitySan Francisco, CA


  • Mach-Zehnder Interferometer (MZI)
  • Optical Column Decoder (CD)
  • Optical memory
  • Optical RAM
  • Optical Row Decoder (RD)
  • Optical signal processing
  • Semiconductor Optical Amplifier (SOA)


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