Opto-acoustic transducer

Golay cell signal receiver

Opto-acoustic transducer operates in the frequency range: 0.02-20TGts. Input window converter 6 mm diameter is made from polyethylene or diamond window that provides permeability to 20 THz. The transmitter includes a built-in preamplifier. For operation of the converter requires a power supply to the + 15V, -15V, 32mA. The design of the inverter is used anti-vibration mounting base sensor, which reduces the noise associated with the vibration.

Technical characteristics of the signal receiver PDA:

    The response at the modulation 12.5Hz 10 + 4 / W
    Sensitivity modulation 12.5Hz 10-8W / H ^ 0.5
    Dynamic range 100nW-1mW
    The maximum output voltage of 3.0V
    The maximum modulation frequency of 50 Hz
    The diameter of 6.0mm internal window
    Operating temperature --- 15 + 25
    Humidity 40-80%
    Dimensions in mm 135H115H120
    Operating pressure, Pa 8.4X10 ^ 4-10.7X10 ^ 4

Opto-acoustic transducer can be used to detect both
pulsed and continuous radiation. However, due to the inertia of 25 ms, the average value recorded for pulsed radiation.
 
pyroelectric detectors

The pyroelectric detector - Receiver pyroelectric Ped

Pyroelectric detectors are based on LiTaO3 crystal and are designed to record the modulated electromagnetic radiation in the millimeter and submillimeter ranges. The signal detector is proportional to the power of the incident radiation. On the detector input is black filter for protection from radiation in the visible and infrared ranges.

Technical characteristics of the pyroelectric detector:

    Frequency range 0.02-3THz
    Average response 1000V / W
    The dynamic range of 1 mW, 10 mW
    Optimal modulation frequency 5-30Hz
    The noise level of 1 mV
    Size, mm 135H40H30

Pyroelectric detectors are operated over a wide frequency range 0-1.5TGts black filter with an input or higher in the near infrared range (black without input filter).

Pyroelectric detectors have a lower response amplitude than the signal receivers PDA, but they have less response time.
Attenuators

Attenuators are used in those cases when it is required to enter the attenuation of the signal power to avoid saturation of the receiving detectors. Below pictures attenuators.

The attenuator is composed of four thin film attenuators with fixed transmittance over a wide bandwidth. The coefficients of the four attenuators transmittance equals: 30%, 10%, 3%, 1%. These attenuators can be used in various combinations, to achieve with small increments of a wide range of attenuation.

For example, the use of attenuators 4 will yield the transmission coefficient T = 0.3X0.1X0.03X0.01 = 9X10-4%. External dimensions attenuators equal to 68 mm, 60 mm aperture.
Meter terahertz radiation power

Spectral range 0.02-20 THz

The wide dynamic range of 100 nW - 1 mW

The power meter uses opto-acoustic receiver (Golay Cell) as a radiation detector. The radiation is modulated by an optical modulator (optical chopper) c frequency of 23 Hz. modulator can be used with a frequency in the range defined by 8 -30 Hz. Measured optical-acoustic signal is detected by the receiver synchronous detector and output via USB interface to a PC.

The meter includes an electronic unit, which provides the following functions:

    power supply Golay Cell
    optical modulator power supply
    amplification and synchronous detection of the modulated signal Golay Cell
    the output of the detected signal and the original signal waveform to the USB interface
    tuning the reference signal phase synchronous detector
    time management savings synchronous detector signal
    audible alarm signal overload Golay Cell

Power supplies

Power supply for terahertz generators.

For power supplies to meet high requirements in the small level of voltage ripple at a wide range of, high speed voltage adjustment, protection of radiators during non-standard situations. Below is a power supply unit image.

The lineup of power supplies consists of 3 versions: VR-3M, VR-6M, VR-6MU.

Lenses and grids

plastic Lenses

D1-outer diameter, D1-diameter aperture, F- focal length.
Model

D1 / D2


F, mm
Lens PL-60 2.75 "/ 2" 60
PL-120 lens

2.75 "/ 2
120

The polarization grating

The polarization grating is one of the key elements in the measurement process.

Requirements to formulate a grating, but these requirements are difficult realizable in practice. Signal transmittance through the grating vector E in the incident wave perpendicular to the wire lattice k1 should be close in a wide frequency range. When E parallel wire grating transmittance should be minimized and is close to 0. The following lattice satisfy these conditions over a wide frequency range.

w-m in wire diameter, T-period grating in microns, the diameter of the aperture A in mm
The outer diameter-retaining ring in mm. These parameters may vary according to customer requirements. Grilles are certified and the consumer is issued a passport on the grid.
The following is a lineup with standard parameters.