调谐特性
All New Focus lasers start out as commercially available semiconductor diode lasers.所有的新焦点激光器作为市售的半导体二极管激光器。 These diodes typically operate with several longitudinal modes lasing simultaneously, leading to low coherence and large linewidths.这些的的二极管通常操作与几个纵模激射同时，低的连贯性和大线宽。 One method of extracting highly coherent light from a semiconductor-based laser requires that you anti-reflection (AR) coat the diode so it acts only as a gain element.提取高度相干光从一个基于半导体激光器的一个方法，要求你防反射（AR）涂层的二极管，因此它的作用仅作为增益元件。 The diode can then be placed in an external cavity that contains wavelength-selective optics so that only a single mode lases at any given time.然后，该二极管可以被放置在一个外部的的空腔，包含波长选择性的光学系统，以便在任何给定的时间内，只有一个单一的模式lases。 True single-mode tuning requires that the optical feedback be dominated by the external optics and not by reflections from the diode facet.真正的单模式的调整需要外部光学系统，而不是由二极管方面的反射光反馈是占主导地位。 We use a proprietary AR-coating process to reduce residual diode reflectivities to below 0.001 which guarantees single-mode operation.我们使用专用的AR涂层处理，以减少残余二极管反射率低于0.001，保证单模工作。
Once the diode is coated, we place it in an external laser cavity that is based on the modified Littman-Metcalf configuration.二极管一旦被涂覆，我们将它放置在一个外部的激光谐振腔是基于改性利特曼梅特卡夫配置。 In this cavity a grazing-incidence diffraction grating and a tuning element provide all the necessary dispersion for single-mode operation the amplitudes of non-lasing modes are suppressed to 40 dB below the lasing mode.在这个空腔掠入射衍射光栅和一个调谐元件提供所有必要的色散单模操作非激射模式的振幅被抑制到40分贝以下激射模。
The wavelength in a modified Littman-Metcalf laser is changed by tilting the retroreflector, which changes the diffracted wavelength fed back into the cavity.通过倾斜的后向反射镜，从而改变反馈到空腔中的衍射波长的改性利特曼梅特卡夫激光器中的波长被改变。 To prevent mode hopping, the cavity length must be kept at a constant number of wavelengths as the laser tunes.为了防止模式跳变，腔的长度必须保持在一个恒定的数量的波长作为激光曲调。 This requires that the pivot point around which the element tilts be positioned with sub-micron accuracy.这需要与亚微米精度定位，围绕该元件的枢转点倾斜。 Using a patented technique for pivot-point location, we produce lasers with no mode hops.利用专利技术为支点的位置，我们生产的无跳模激光器。 For all of lasers we can guarantee absolutely no mode hops over the entire specified tuning range.对于所有的激光器，我们可以保证绝对无跳模在整个调谐范围。
If the laser does mode hop, the frequency change will be 3 GHz, which is equal to the external-cavity free-spectral range.如果激光确实跳模，频率的变化将是3千兆赫，这是等于外腔的自由光谱范围。 (In contrast, for a poorly coated diode laser, it can be as much as 100 GHz.) We individually test every laser we build and ship them with printouts of their tuning curves, so you'll know exactly what to expect from your laser. （相反，不良的涂层激光二极管，它可以高达100 GHz的）。我们分别测试每一个我们建立的激光，并运送他们的调谐曲线与打印输出，所以你确切地知道什么期望从你的激光。 (Please contact us if you would like to see sample tuning curves in your wavelength range.) （请联系我们，如果你想看看样品在您的波长范围内的调谐曲线）。
The lasers will operate best in a temperature range from 15 to 35 °C, outside of which we can no longer guarantee single-mode operation.激光器将操作最好在温度范围从15至35°C，其中之外，我们可以不再保证单模操作。
For our TLB-6700 Velocity™ Widely Tunable Lasers , we separate wavelength tuning of our lasers into coarse and fine tuning.对于我们的TLB-6700速度™的广泛可调谐激光器 ，我们把我们的激光器的波长调谐到粗，微调。 Coarse tuning is accomplished by using a DC motor to turn a precision screw.粗调是通过使用直流电动机转动一个精密螺钉。 An angle sensor incorporated in the laser cavity feeds back to the microprocessor to scan to the desired wavelength.结合在激光腔的角度传感器反馈到微处理器扫描到所需波长。 On the end of the coarse-tuning screw is a piezoelectric actuator.粗调谐螺钉的端是一个压电致动器。 This actuator provides independent fine control of the laser wavelength and can be used to modulate the laser frequency while it is being slowly scanned.该致动器提供了独立的精细控制的激光波长，可以用来调制激光的频率，而它被缓慢扫描。 Our TLB-6900 Vortex™ II Tunable Lasers and StableWave Tunable Lasers use this same fine-tuning piezoelectric mechanism.我们的TLB-6900涡™II可调谐激光器和StableWave可调谐激光器使用相同的微调压电机制。
The coarse tuning mechanism on the Velocity lasers allows you to set the wavelength with a resolution of 0.02 nm.粗调机制的速度激光器可让您设定分辨率为0.02 nm的波长。 The fine-frequency tuning resolution of the Velocity, Vortex, and Stablewave lasers is 10 MHz or about 2x10-5 nm when using the controller, with a range of approximately 0.2 nm.细的速度，涡，和Stablewave激光器的频率调谐分辨率为10 MHz或约2×10-5纳米时使用的控制器，一个范围约0.2纳米。
There is roughly a 5% drift on the piezo over a period of several seconds after a significant wavelength change as the piezo relaxes.是压电的漂移大约5％，过一段几秒钟后，显着的波长变化作为压电放松。 There should not be any significant amount of shift in wavelength from the wavelength displayed on the screen.不应该有任何显着量的从在屏幕上显示的波长的波长移位。
If you want to perform high-resolution wavelength scans over a narrow wavelength range, use the analog Frequency Modulation input on the back panel of the laser controller.如果你想在一个狭窄的波长范围内进行高分辨率波长扫描，使用的模拟频率调制的激光控制器后面板输入。 The reason for this is that the electronic gain of the Frequency Modulation input can be selected to be either 25x or 1x.这样做的原因是，可以选择输入的频率调制的电子增益是25倍或1x。 This can only be done with the Vortex laser system, and it requires issuing a command through the GPIB or RS-232 interface.这只能涡的激光系统，它需要发出命令通过GPIB或RS-232接口。 By selecting the 1x gain for the Frequency Modulation input, the frequency resolution of the Vortex will be very high because it is less susceptible to electronic noise pick-up from the analog input signal.通过选择1个增益的频率调制输入，涡街的频率分辨率是非常高的，因为它是那么容易接机的模拟输入信号的电子噪音。
The output beams from all New Focus tunable lasers are linearly polarized in a vertical plane.从所有新焦点可调谐激光器的输出光束在垂直平面内的线偏振光。 The polarization ratio for our lasers near 633nm is 50:1 and the polarization ratio for all other lasers is 100:1.我们近633nm波长的激光的偏振比为50:1和所有其他类型的激光器偏振比为100:1。
All of our lasers are nearly diffraction-limited, because they operate in the fundamental transverse mode (because of the high divergence of some diodes, you may see some clipping effects on the output beam).我们所有的激光器是近衍射极限的，因为他们工作的根本横向模式（因为高分歧的一些二极管，你可能会看到一些剪裁的输出光束的影响）。 For most of our TLB-6900 Vortex™ II Tunable Lasers , Velocity™ Widely Tunable Lasers and StableWave Tunable Lasers, the beam shape is elliptical, with approximately a 3:1 aspect ratio.对于大多数我们的TLB-6900涡™II可调谐激光器 ， Velocity™系列产品广泛可调谐的激光和StableWave可调谐激光器，光束形状是椭圆形，约3:1的宽高比。
We use a single mode PM (polarization maintaining) Panda fiber with a cladding diameter of 125 µm and a 3mm jacket.我们使用一个单一的模式PM（偏振保持）熊猫光纤包层直径为125μm和3mm夹克。 Both ends are terminated with FC/APC connectors with a wide key that is pre-aligned and locked to the slow axis.两端被终止与FC / APC连接器具有宽密钥预先对准和锁定的慢轴。 The coupling loss from the laser to the fiber pigtail is 3 dB.从激光到光纤尾纤的耦合损耗为3 dB。 In other words, the typical coupling efficiency into the fiber pigtail is 50%.换言之，进入光纤尾纤的典型的耦合效率是50％。 The PM fiber is aligned with the polarized axis to within two degrees of the output polarization of the laser. PM光纤与偏振轴对准的激光的输出偏振的两自由度内。 This results in an 18 to 20-dB polarization ratio (approximately 100:1).这样的结果在18至20分贝的偏振比（约100:1）。
In constant-current mode, the frequency drift of the laser is less than 0.02 nm over an entire day and less than 5 MHz over a one-second interval.以恒定电流模式下，激光的频率漂移是小于0.02 nm的整个天，超过一秒钟的时间间隔小于5MHz。 Stabilizing the frequency of the laser is easy with an error feedback signal to the Frequency Modulation input on the back panel.稳定的激光的频率是容易带有错误反馈信号的背面面板上的频率调制的输入。 Using this technique, wavelength drift can be dramatically reduced.使用这种技术，波长漂移，可显着减少。
The laser can easily be locked either to an atomic line or to an external cavity using wavelength modulation techniques to produce a feedback signal.激光可以容易地被锁定到一个原子的线或使用波长的调制技术，以产生反馈信号的一个外腔。 Dither the laser frequency through the Frequency Modulation input.通过频率抖动的激光频率调制输入。 The error signal generated can then be fed back to stabilize the laser.产生的误差信号，然后，可以反馈，以稳定的激光。
The minimum frequency shift that is observable over the frequency jitter of the laser is 1 MHz.最小频移为1 MHz以上的频率抖动的激光可观察。
While you can modulate the wavelength by scanning the drive motor (coarse tuning) or by changing the laser-drive current, the most straightforward way to modulate the laser wavelength is by changing the voltage to the PZT actuator on the tuning element.尽管你可以调节的波长扫描驱动电机（粗调），或通过改变激光器的驱动电流，最简单的方法来调节激光的波长是通过改变电压的压电陶瓷驱动器的调谐元件。 The small-signal bandwidth of the fine-frequency input is 2 kHz in the Velocity lasers and 3.5 kHz in the Vortex and Stablewave lasers.优良的频率输入的小信号带宽的速度激光器为2 kHz，3.5 kHz的的旋涡和Stablewave的激光器。
The voltage that you apply at the Frequency Modulation Input is amplified by an analog high-voltage amplifier, and then applied to the piezo.适用于以下的频率调制的输入的电压是由一个模拟高电压放大器放大，然后施加到压电。 This circuit does not have a DA converter.该电路不具有DA转换器。 Therefore, you should see a smooth fine-frequency tuning response when you apply an analog signal to the Frequency Modulation Input.当你申请一个频率调制输入的模拟信号，因此，你应该看到一个光滑精细的频率调谐响应。
If a computer is used to control the fine-frequency tuning of the laser, then the resolution will be approximately 100 MHz or less.如果使用一台计算机来控制微细的频率调谐的激光，则分辨率将是约100 MHz或以下。 The reason for this is that when using a computer, the minimum step size of the piezo voltage is 0.1 volts.这样做的原因是，在使用一台计算机时，在压电电压的最小步长为0.1伏。 A 0.1-volt voltage change on the piezo corresponds to a frequency shift of approximately 100 MHz. 0.1伏的压电元件上的电压变化对应于约100兆赫的频率漂移。
The Velocity, Vortex, and Stablewave lasers have a minimum frequency resolution of 10 MHz (or, 2x10-5 nm).速度，的涡，和Stablewave激光器有一个最小频率分辨率为10 MHz（或2×10 - 5纳米）。 However, the only way to access this minimum frequency resolution is by using the Frequency Modulation input on the back panel of the laser controller.然而，唯一的方式来访问这个最低的频率分辨率是通过使用背面板上的激光控制器输入的频率调制。 The Frequency Modulation input is an analog voltage input that is used to control the piezo voltage.的频率调制的输入是一个模拟电压输入，用来控制压电电压。
So, if you want to perform a wavelength scan with a frequency resolution of 10 MHz, then you will need to supply a low-noise analog voltage signal to the Frequency Modulation input.所以，如果你要进行波长扫描分辨率为10 MHz的频率，那么你将需要提供一个低噪声的模拟电压信号的频率调制输入。 Alternately, if you want to scan the laser wavelength in 0.001 nm steps (or, approximately 300 MHz frequency steps), then you can use the computer interface to change the piezo voltage in 0.1-V steps.另外，如果你要扫描的激光波长为0.001 nm的步骤（或约300 MHz的频率步长），那么你可以使用电脑的接口改变压电电压在0.1-V步骤。
The input impedance is 4 k Ω.输入阻抗为4 KΩ。 The input protection circuit consists of two 4-V Zener diodes tied to ground输入保护电路由两个4-V的齐纳二极管连接到地面
If you're working with unterminated fibers, you may be concerned about possible coherence effects due to the narrow linewidth.如果你的工作未结束的纤维，你可能会担心可能的相干效应的窄线宽。 For most measurements, a simple way to make the linewidth appear much broader is to apply a signal to the piezo in order to frequency modulate the laser.对于大多数的测量，一个简单的方法，使线宽更广泛的出现是应用到压电信号，以便调制激光频率。
The amplitude stability of our Velocity lasers over 10 seconds is better than 0.25% at any given wavelength.我们的速度激光器的振幅稳定性优于0.25％，在10秒内，在任何给定的波长。 In stable-power mode, the amplitude is typically constant to within ±5% as the laser is tuned.振幅在稳定的功率模式下，通常是常数，以在±5％之内，作为激光器被调谐。 (Stable-power mode is available only for scans at less than 1% of the maximum scanning speed and it is not available at all wavelengths.) To prevent optical feedback from affecting the laser's performance, we recommend using an optical isolator with our free-space lasers. （稳定的电源模式只用于扫描的最大扫描速度小于1％和它是不是在所有波长。）为了防止光反馈影响激光器的性能，我们建议使用光隔离器与我们的自由空间激光器。 To prevent étalon effects in free space or fiber components, which could create amplitude modulation while scanning, we recommend slightly tilting your optics and using FC/APC fiber connectors.为了防止在自由空间或纤维成分，可以创建振幅调制，而扫描的标准具效应，，我们建议稍微倾斜的光学和使用FC / APC光纤连接器。
The intensity noise of our ECDLs is directly related to the current noise in the laser-diode drive current.直接相关我们ECDLs的强度噪声中的激光二极管的驱动电流的电流噪声。 In constant-current mode, the intensity noise of the laser output is limited by the current noise of the drive electronics.以恒定电流模式下，噪声强度的激光输出的驱动器电子电路由电流噪声的限制。 Our low-noise controllers make our systems among the quietest ECDLs available at <0.1% RIN.我们的低噪声控制器使我们的系统，也是最安静的ECDLs <0.1％RIN。 In stable-power mode, the current noise is necessarily increased by the feedback mechanism.在稳定的功率模式下，电流噪声必然是增加的反馈机制。 This results in small increases in both short-term intensity noise and linewidth.这样的结果在短期噪声强度和线宽的小幅增长。
You can modulate the laser current by applying analog voltages to the Current Modulation Input at a rate of up to 1 MHz with a modulation amplitude of up to 2-mA peak.您可以调制的激光通过施加电流调制输入的模拟电压在最多为1 MHz的速率与调制振幅高达2-mA峰值电流。 You can also modulate the laser's amplitude with a bandwidth of 100 MHz and an amplitude of up to 10-mA peak through the SMA connector on the laser head.你也可以调节激光的振幅用的带宽为100 MHz和振幅高达10-mA峰值通过SMA连接器上的激光头。 Small changes in the index of refraction of the laser-gain medium as a function of laser current leads to changes in the laser wavelength when the current is modulated.作为一个功能的激光电流引线的变化中的激光波长，当电流调制的激光增益介质的折射率在索引中的小的变化。 The wavelength-modulation coefficient depends strongly on each laser diode's characteristics, but is typically 50 MHz/mA and at most 1 GHz/mA.的波长调制系数强烈地依赖于每一个激光二极管的特性，但一般为50 MHz / mA和至多1 GHz的/毫安。
The input impedance is 5k Ω and conversion is 0.2mA/V.输入阻抗5KΩ和转换0.2毫安/ V。
Yes.是。 The same controller will work with any laser head in its family.在同一个控制器工作与任何激光头在其家庭。 However, for the TLB-6700 Velocity™ Widely Tunable Lasers , wavelength calibration for each laser head is guaranteed only when it is used with its original controller.然而，对于TLB-6700速度™的广泛可调谐激光器 ，波长校准为每个激光头只保证使用时，其原有的控制器。 Laser heads will not work with controllers from other families.与其他家庭控制器，激光头将无法正常工作。 (When ordering additional laser heads for a controller, initial calibration of the head to the controller may be required.) （为控制器订货时额外的激光头，头到控制器的初始校准可能需要）。
Prealigned optics give you no-fuss interchangeable heads.预校准光学没有给你大惊小怪互换头。 Positioning the laser-cavity optics for mode-hop-free tuning is a time-consuming task, and the New Focus approach to changing wavelengths takes this burden off your shoulders.激光腔的光学定位模式跳免费调音是一个耗时的任务，新焦点的方法来改变波长你肩上的负担。 We do all the precision adjustments at our factory and send you a sealed, adjustment-free laser head.在我们的工厂，我们做所有的精密调整，并给你一个密封的，调整激光头。 Should you need another wavelength outside the range of your first laser head, you can simply plug in a different laser head, with no adjustments needed.如果你需要另一种波长的范围之外，你的第一个激光头，你可以简单地插在不同的激光头，没有必要的调整。 (When ordering additional Velocity laser heads, initial calibration of the head to the controller may be required.) （订货时，可能需要额外的的速度激光头，头到控制器的初始校准）。
Each controller can operate one laser head at a time.在一个时间，每个控制器可以操作一个激光头。 To operate two lasers simultaneously, you need two controllers.两束激光同时运作，你需要两个控制器。
