Exceed fast laser to have energy density tall, directional strong, coherence is advanced characteristic, treatment of small pay of flying second laser is in complex three-dimensional the treatment domain of parts of an apparatus of small accept function has distinct advantage. At present processing technique all is traditional laser small accept the treatment means that pointwise scans, those who machine efficiency to cannot satisfy actual production is efficient demand. The computation that is based on dimensional smooth modulator is holographic the smooth field that the technology can realize to be able to accuse neatly distributings, flying second laser can be become by accurate modulation the array of much focus design that sets beforehand, realize efficient collateral treatment thereby, can greatly improve treatment efficiency. Use what dimensional smooth modulator can go to the lavatory to make beam of light of Bei Sai Er at the same time, second exposure type machines the sheet that can achieve small annular structure.
Dimensional smooth modulator exceeds fast laser small accept to machine small accept to machine laser beam machining
Dimensional smooth modulator (SLM) can go to information to load in field of data of 2 dimension optics, it is a kind of parts of an apparatus that undertakes adjustment to beam of light. Through controlling to load the gray scale to SLM pursues, SLM is OK the phasic, amplitude of smooth field of adjusting control space, polarization, what perhaps realize light is incoherent the sexual change to coherence. Exceed SLM fast laser small offer together processing technique union rises, produce the advantage of both, can increase the efficiency that laser small accept machines and flexibility greatly. Be like: The array that uses SLM to produce much central issue (E.g. 30×30) , from 1 the dot turns 900 into the dot, treatment efficiency raises 900 times. Pass the niche that dominates each dots at the same time, can realize diverse line the control of wide different Jiao Shen. SLM still can pass hologram of to load computation, the one-time exposure that can realize design construction is machined.
Graph 1 use SLM to create much focus array and collateral treatment pattern
Graph the dimensional smooth modulator on 2 market (SLM) product give typical examples
SLM besides can adjust laser to generate 2 dimension much focus to cooperate floating platform or Zhen Jingjin to chase a scanning to realize three-dimensional treatment all right, SLM still can become modulation of flying second laser the space specific the efficient treatment that dimensional lattice, line smooth field, face smooth field, implementation is primary treatment unit with dot, line, face. Outside distributinging except 2 dimension smooth field, SLM can undertake modulation of three-dimensional light field.
Smooth modulator produced the space of P1920-400-800-HDMI of bit-type of liquid crystal simple look that Shanghai Hao measures the technical engineer of photoelectricity equipment limited company to manage company of American Meadowlark Optics 2×2, 2×3, the lattice of dimensional gauss facula of 2×4 and lattice of facula of Er of dimensional Bei Sai.
Solid optometry road is as follows:
Experimental result is as follows:
Graph 3 2×2, 2×3, the dimensional gauss facula of 2×4 orders a kill
Graph 4 2×2, 2×3, the facula of Er of dimensional shellfish a place of strategic importance of 2×4 orders a kill
Exceed fast laser small accept to machine the requirement of smooth to the space modulator
The scathing threshold value of 1.SLM
Because SLM is incident illumination cent many focuses. Increase as what anxious check the number measures, the power of every focus drops. To increase focal amount, the power that retains every focus at the same time satisfies the requirement that small accept machines, the scathing threshold value of SLM is gotten crucial. Many elements affect the scathing threshold value of SLM. : 1, the size connecting light that increases SLM allows illume to distributing to be able to be optimized in the electrode coating of bigger area;2, SLM absorb in order to restrict, raise reflectivity to be able to use Yu Huan;3, actively to see fuel factor with passive and cooling system, assure the stability of phasic modulation voltage.
At present the SLM main brand on market resembles German Holoeye, american Thorlabs, taiwan JDC, and a few homebred SLM, its injure threshold value to all be 2W/cm2, drop in temperature without water-cooling module.
The scathing threshold value of the smooth modulator of 1920×1152(P1920) series space of company of American Meadowlark Optics can amount to 200W/cm2, deploy water-cooling module, the temperature that assures liquid crystal is constant, phasic modulation deepness is constant.
2.The noise of SLM is in season (refresh speed)
Liquid crystal answers time to depend on many elements, include the ply of liquid crystal layer, after its are optimized, be in in wavelengh of the chiefest job offer wave of a phasic journey, the voltage of driver and liquid crystal material are characteristic. To smooth genetics, most researcher combines microscope of SLM and double photon, 3 photon, and work come in 900 Nm inside the wavelengh limits of 1300 Nm. Company of American Meadowlark Optics is the supplier that offers high speed SLM exclusively, smooth modulator of space of HSP1920-1064-HSP8 liquid crystal is in 1064 Nm, the liquid crystal that can achieve 300 Hz answers speed (change from 0 – 2pi) the frame frequency with 845Hz (gray scale picture transmits SLM speed) with computer.
Be in 1064 Nm place, liquid crystal from 10% to 90% limits Neishangsheng and decay time are less than 3 Ms. Open the central point through sparking and spark shut undertake detecting. (Left) time by software the liquid crystal switch of drive. The focus is opened and shut detector (show for maize) . When the image on SLM produces change, hardware can produce an output pulse (show) with purple, state new image will begin to be on SLM inside 1.18 Ms to load. (Right) spark by exterior hardware the liquid crystal switch of drive. When the fall of exterior trigger the edge arrives (show with blue) when, hardware will start the image on SLM to update. Generation output pulse is received with affirming spark (show) with purple. Inside the 1.18 interview after generation outputs pulse, image will be newer on SLM (show with yellow, the focus is immigrant and move a detector) .
At present the SLM main brand on market resembles German Holoeye, japanese bank is loose, american Thorlabs, taiwan JDC, and a few homebred SLM, its liquid crystal answers time to be controlled in 80ms(12.5Hz) in 1064nm, the frame frequency of controller all is 60Hz.
Exceed fast laser small accept to machine the consistency when allocating to ensure each focus is in, the time response of SLM becomes important. The SLM of Meadowlark Optics company uses two kinds of strategy to come the biggest change phasic stability. The first kind of strategy is to use direct imitate to find site, is not imitate uses a binary system to search location and sequential to shake the imitate modulation that is united in wedlock. The 2nd kind of strategy is to use can the custom-built backboard of the rate refresh with 844Hz. The voltage loss that refresh of high speed backboard resembles element capacitance to reducing is necessary. If backboard refresh is slower, the tension that handles like element drops make liquid crystal element flabby, change the refractive index of LC thereby. Pleased if the refresh speed of backboard voltage is apparent quickly at LC relax time, so SLM will have taller phasic stability.
Repeat phasic brae through be being written to SLM and measure first-order intensity to quantify photograph stability. The instability with LC flabby element can bring about the intensity of first-order focus to change along with time. Photograph stability is gone to for the peak by the definition the ratio of the peak value of first-order focus strength and strength of average central issue. The research of taller to need phasic stability and high resolution, standard 1920 X 1152 can be offerred like element SLM low to the phasic ripple of 0.20% .
4.The quality before wave (the distortion before wave)
Odd photon arouses photograph comparing, double photon arouses the limitation with be had better, because by two photon the square of the possibility that arouses at the same time and luminous intensity becomes direct ratio. Accordingly, double photon arouses the 4 power attenuation that is apart from with the focus  . However, this kind low excitation possibility makes operation pattern right those who change focal PSF is sensitive like difference. Arouse consistently on large volume to ensure, of the SLM in corrective microscope and component of the others optics resembling difference is very important.
A lot of at token and the algorithm with school poor positive-appearing image using that be based on Zernike multinomial. However, do not apply to those who describe square or rectangular array to resemble difference to the dependence of circular aperture. Had developed the interference that is based on SLM child of bore diameter replace strategy  , in order to ensure on the valid area of SLM OK like difference by corrective arrive λ/ 40 or better. If the graph is shown 7 times, because used workmanship, difference resembles before the wave of the itself of MLO SLM very low.
(Before the 1920 X 1152 with primitive A) resembles element SLM wave (before λ/ 7 RMS)(b) used corrective like difference wave (λ/ 20 RMS)(c) did not use figure of corrective curved surface resembling difference. (The curved surface resembling difference after C) application is corrective pursues.
5.Computation is holographic and algorithmic optimize
Company of American Meadowlark Optics and American Howard rest the researcher joint development of Si Duixue courtyard newest computation is holographic optimize algorithm, and embed arrive in the control software of SLM, the facula mode that the client’s OK and correct, agile more convenient generation wants. At the same time the user can control the light intensity of every focus according to his demand.