ErAs:In(Al)GaAs Terahertz Transceivers for Compact Pulsed Free Space Photonic Vector Network Analyzer

Abstract We present ErAs:In(Al)GaAs-based terahertz transceiver modules, comprising transmitter and receiver components integrated on a single chip. The transceiver module is employed in a two-port single-path (TxRx-Rx) or 1.5-port pulsed free space photonic vector network analyzer setup, wherein the second receiver is an individual ErAs:InGaAs photoconductor. This configuration allows for simultaneous extraction of transmission and reflection coefficients or scattering parameters $$S_{21}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>S</mml:mi> <mml:mn>21</mml:mn> </mml:msub> </mml:math> and $$S_{11}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>S</mml:mi> <mml:mn>11</mml:mn> </mml:msub> </mml:math> . The system achieves a peak dynamic range of $$\sim $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>∼</mml:mo> </mml:math> 59 dB for $$S_{21}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>S</mml:mi> <mml:mn>21</mml:mn> </mml:msub> </mml:math> and $$\sim $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>∼</mml:mo> </mml:math> 43 dB for $$S_{11}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>S</mml:mi> <mml:mn>11</mml:mn> </mml:msub> </mml:math> at a bandwidth reaching $$\sim $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>∼</mml:mo> </mml:math> 3.5 THz for the transmission and $$\sim $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>∼</mml:mo> </mml:math> 2.5 THz for the reflection path. These values are obtained by averaging over 500 traces at a scan rate of 4 Hz. The system exhibits superior frequency coverage compared to commercially available electronic vector network analyzers, thus offering a compact, cost-effective, broadband characterization solution for the benchmarking of terahertz devices and components.