Abstract: A mail screening apparatus is provided to perform the inspection of mail or similar objects. Terahertz inspection is used to localize potential suspicious areas by imaging the contents inside the envelope or small parcel. The mail screening apparatus includes a primary and a secondary inspection zone, preferably allowing inspection of the mail in a normal and a zoomed mode, respectively. The same light source, image capture device and intervening optical components are used in both normal and zoomed modes. Metal detection may optionally be used to enhance awareness in the presence of metallic content. In one implementation, metal detection zones are provided in an orthogonal configuration with respect to the primary inspection zone used for terahertz imaging to accommodate for both manual and automatic inspection of mail.

Abstract: A new class of efficient vacuum electronic devices (VEDs) for THz wave generation and amplification are disclosed. The EM circuits of these VEDs are micro-fabricated from Si wafers with high precision. The original design of the EM circuits overcomes the main limitations of existing THz VEDs constructed from metal or metallized components, such as low fabrication precision, high signal losses, low tolerance to electric breakdown and low beam efficiency. The disclosed VEDs may have up to 50% beam efficiency in the THz band.

Abstract: A mail screening apparatus is provided to perform the inspection of mail or similar objects. Terahertz inspection is used to localize potential suspicious areas by imaging the contents inside the envelope or small parcel. The mail screening apparatus includes a primary and a secondary inspection zone, preferably allowing inspection of the mail in a normal and a zoomed mode, respectively. The same light source, image capture device and intervening optical components are used in both normal and zoomed modes. Metal detection may optionally be used to enhance awareness in the presence of metallic content. In one implementation, metal detection zones are provided in an orthogonal configuration with respect to the primary inspection zone used for terahertz imaging to accommodate for both manual and automatic inspection of mail.

Abstract: A mail screening apparatus is provided to perform the inspection of mail or similar objects. Terahertz inspection is used to localize potential suspicious areas by imaging the contents inside the envelope or small parcel. The mail screening apparatus includes a primary and a secondary inspection zone, preferably allowing inspection of the mail in a normal and a zoomed mode, respectively. The same light source, image capture device and intervening optical components are used in both normal and zoomed modes. Metal detection may optionally be used to enhance awareness in the presence of metallic content. In one implementation, metal detection zones are provided in an orthogonal configuration with respect to the primary inspection zone used for terahertz imaging to accommodate for both manual and automatic inspection of mail.

Abstract: A mail screening apparatus is provided to perform the inspection of mail or similar objects. Terahertz inspection is used to localize potential suspicious areas by imaging the contents inside the envelope or small parcel. The mail screening apparatus includes a primary and a secondary inspection zone, preferably allowing inspection of the mail in a normal and a zoomed mode, respectively. The same light source, image capture device and intervening optical components are used in both normal and zoomed modes. Metal detection may optionally be used to enhance awareness in the presence of metallic content. In one implementation, metal detection zones are provided in an orthogonal configuration with respect to the primary inspection zone used for terahertz imaging to accommodate for both manual and automatic inspection of mail.