Too hertz (Tera Hertz, abbreviation THz) wave it is to show frequency is in normally 0. 1 ～ 10 THz (wavelengh is in 0. 03 ～ 3 Mm) the electromagnetic wave of wave band, we feel the presence that is less than it, but it is honest however the ground around it is all round us.

The long wave band of THz and millimeter wave (inferior millimeter wave) photograph coincide, its develop science and technology of main support electronics, and its short wave band and infrared ray (outside Yuan Gong) photograph coincide, its develop main support photon to learn science and technology, wave of place aether hertz is the alternate territory that macroscopical electronics and microcosmic photon learn to consider. This also decided the development way of source of current and main THz, it is the laser optics technology that aether hertz laser is a delegate firstly, include aeriform laser, semiconductor laser and electronic laser to wait, this kind of technology comes from the development at direction of laser technology Xiang Changbo; It is the vacuum electron technology that is a delegate with microwave component secondly, include source of microwave of microwave canal, solid and diode of brighting family name to wait, this kind of technology comes from Yu Weibo technology the development to shortwave direction; It is to exceed fast laser technology thirdly, this kind of technology is THz is mixed to low frequency high frequency develop at the same time.

 

Graph 1. THz radiate is in the position in electromagnetic wave chart.
 

But, spectral analysis domain 0. 5 ～ 5 THz just has important sense, basically have two kinds of methods at present, the indirect method that can adopt laser technique is obtained. (1) the photocurrent in relying on antenna of fast modulation semiconductor; (2) use exceed switch of photoelectricity of illuminate of short pulse laser. What these two kinds of methods use is visible close perhaps infra-red laser: Former use successive and adjustable diode laser, latter uses flying second fiber-optic laser.
 

TOPTICA Photonics company is distributed to using feedback diode laser and fiber-optic laser produces flying second two kinds this too the method of hertz electromagnetic wave undertook analyse and be comparatived, built mature and outstanding product. At present TOPTICA can be time domain of frequency domain ／ too hertz application offers a variety of solutions, component and product, all these component are completely modular, and can ask according to the experiment be combined or upgrade.
 

 

Platform of spectrum of frequency domain of graph 2 TeraScan

 

Diagram of structure of graph 3 TeraScan
 

Successive and adjustable of humorous too the poor frequency of the laser that hertz wave can grow through having Xiang Linbo twice mixes will obtain, if pursue 2, graph 3. Electromagnetic wave overlay is in the structure of antenna of a semiconductor, for instance arsenic changes gallium (GaAs) , this structure serves as too the radiation source of hertz wave. Of two kinds of different frequency stimulate beam of light to produce photocurrent in semiconductor, through adjusting the difference on the frequency of these two bundles of laser, can obtain different frequency too hertz wave.
 

Wavelengh is in the distributinging feedback type near 800nm (DFB) laser is special apply to generation but harmonious too hertz wave. Its are main the advantage is output power is tall, adjustable humorous frequency range is wide and emissive wavelengh is taken under GaAs unoccupied place. Use center wavelengh can be obtained for the laser near 780 Nm 0. 4 ～ 2. The electromagnetic wave of 2 THz harmonious limits (if pursue 4) ; The laser near use 1550 Nm (InGaAs antenna) can win frequency range for 0. 1 ～ 2. The electromagnetic wave of 9 THz (if pursue 5) . Of the major gas that uses on industry, chemical reagents and dynamite draw wave band by these too place of hertz electromagnetism wave band is enclothed.

 

Graph 4 TeraScan 780

 

Graph 5 TeraScan 1550

TeraScan technology parameter

 

If the experiment needs higher power (premise is smooth blender also have enough scathing threshold value) , graph the system of 3 can be changed advocate system of oscillation power amplifier. Laser of such 2 DFB semiconductor are entered by coupling at the same time in amplifier of same table semiconductor, this amplifier can output power to be the beam of light of the close diffractive limit of 500 ～ 1000 MW. Meanwhile, the harmonious limits of DFB semiconductor laser and spectral property keep changeless.

In addition, TOPTICA developed a kind of technology locking up a model that is based on orthogonal interferometer, this technology can pass computer control, obtain frequency error to be in the frequency height of 1 MHz is accurate too hertz wave, will come true certain and accurate detect and measure those who measure harmful gas to measure surely.

 

Graph the experiment of platform of spectrum of frequency domain of use TeraScan of 6 northing teacher checks a result

 

Too the radiation cause that hertz pulse electromagnetic wave adopts flying second laser and semiconductor antenna composition will obtain. Load of report of incident generation freedom sheds the flying second pulse of use 1560nm child, these carrying stream child can quicken below the action of interiorly or exterior electric field, of electric current connect those who caused a kind of provisionality, the electromagnetism field that has range of wide extensive spectrum. Such, inside close infra-red and spectral limits correspondence is at spectral line limits 0. Width of 1 ～ 5 THz, pulse is ＜ 60 Fs too pulse of hertz electromagnetic wave arose. Too one of plan of hertz radiate source are use miniaturization, price reasonable and dependability exceeds fast fiber-optic laser by force. Glass of mix into Erbium is fiber-optic the laser that flying second laser can output wavelengh to make an appointment with width of 1560 Nm, pulse to be less than 60 MW of prep above of 60 Fs, average power bundle. The flying second that Toptica still provides higher power is fiber-optic laser. The fiber-optic laser of TOPTICA company arises too it is OK that the letter a confusion of voices of hertz electromagnetic wave is compared with use titanium – sapphirine laser obtains too the letter a confusion of voices of hertz electromagnetic wave is compared be likened to.

 

Platform of spectrum of time domain of graph 7 TeraFlash
 

 

Diagram of structure of graph 8 TeraFlash
 

 

Graph 9 TeraFlash1560

 

 

 

Apply the demand that the domain increases increasingly in the light of nondestructive test, TOPTICA expanded further its too hertz instrument combination. Be in this year Photonics West, roll out a new product – into the time domain that resembles expanding too TeraFlash of hertz spectrum platform. The bandwidth as a result of the spectrum with distinctive TeraFlash (0. 1 – 5 THz) , researcher can make full use of it becomes the latent capacity that resembles be united in wedlock with spectral photograph.

Into resemble expanding use two accurate linear platform, pass focusing too sample of scanning of hertz beam of light. The defer component in translation motion and TeraFlash is synchronous, accelerated significantly measure speed, allow a system to be as high as 16 speed that resemble element to collect complete weaveform with every second, in 15×15 centimeter excel of precision of the fixed position inside visual field 200 micron.

The expert of TOPTICA and institute of German Berlin Fraunhofer Heinrich Hertz develops jointly into resemble expanding have two version – the researcher of the optical cell that uses oneself for the hope offers version of “ basic ” , and the “ that includes the paraboloid illuminator that is used at plastics of beam of light and focusing is complete ” version. Become thoroughly resemble expanding provided distinctive flexibility: Have the aid of is right cite a base together, the user is OK and frequent will optical component installs new configuration to be reflection from transmission, vice versa.

Two kinds of version have the software with powerful function to wrap, can offer a variety of contrast parameter, include amplitude, phasic with layer ply. In addition, the user can filter in time domain and frequency domain primitive data, generate extent and height to distributing along the aleatoric cross section of example.
 

 

Too hertz becomes complete like what expand version, reflex (left) with transmission (right)

The following picture all checks for Toptica product
 

 

The article inside the boot that install check identifies

 

The article inside the envelope identifies

 

Gasbag builds the security that takes a line to resemble

 

Of the plastic wedge that contains bleb into picture

Too hertz technology is usable still at biology medicine, safety is monitored and wireless electrify mixes flaw detection of quality control, nondestructive, close quarters network, national defence application. Future, as too of hertz technology increasingly mature, too hertz application technology will surely be applied extensively. Fiber-optic technology and product of optical data storage reach the diode laser that TOPTICA precedes as industry, flying second technical supplier, what can increase scientific research continuously is devoted, roll out more advanced product.