Terahertz Emitter

LT-GaAs 1900,- EUR (Excluding VAT)  
GaBiAs   2500,- EUR (Excluding VAT)   

Principle of Operation

Free space THz emitter consists of a micro strip antenna integrated with photoconductor and silicon lens mounted on the back side of photoconductive antenna.

Low temperature grown GaAs (LT-GaAs) or GaBiAs is used as photoconductor. Semiconductor material depends on laser wavelenght. Total GaAs substrate thickness is about 600 µm. Antenna is formed using AuGeNi metallization.

THz emitter is illuminated by laser beam from panel side. Laser beams must be focused between two Ti/Au strip lines (Fig. 1). Si lens is used for THz radiation output. Adjustment screws are used for Si lens positioning in point of view of microstrip antenna center. SMA socket is used for connecting DC or AC bias to THz emitter. Any of three M6 holes can be used for THz emitter mounting on optical table.

Fig 1. Microstrip antenna drawing

Standard Specifications

LTG-GaAs based photoconductive switch:

  • Dimensions of the wafer: 5x1.5 mm typical
  • Emitted power: more than 10 µW typical @ 30 mW pump and 40V bias
  • THz pulse duration: see Fig. in detector page for typical waveform.
  • Bias voltage: 50 V max 40 V typical
  • Pumping wavelegth: 800 ± 40 nm.
  • Pumping power: 50 mW max 30 mW typical
  • Integrated focusing lens: Si.
  • X-Y adjustable stage range: ± 3 mm

Fig 2. LTG-GaAs TERAVIL THz emitter radiated power dependance on bias voltage and laser excitation power. Measured using TYDEX Optoacustic detector GC-1P (Gollay Cell).

GaBiAs based photoconductive switch:

  • Dimensions of the wafer: 5x1.5 mm typical
  • Emitted power: see Fig. below for average THz power.
  • THz pulse duration: see Fig. below for typical waveform.
  • Bias voltage: 40 V max typical
  • Pumping wavelegth: 1050 ± 40 nm.
  • Pumping power: < 50 mW
  • Dark resistance > 30 Mohm
  • Integrated focusing lens: Si.
  • X-Y adjustable stage range: ± 3 mm

Fig 3. GaBiAs TERAVIL THz emitter radiated power dependance on bias voltage and laser excitation power. Measured using TYDEX Optoacustic detector GC-1P (Gollay Cell).