Laser module and method thereof

Abstract

Disclosed is a laser module and method for a laser system that expands clinician options when using lasers in medical procedures, such as holmium lasers in urological procedures. The laser module includes independently drivable laser generating assemblies, laser optics, and a driver that drives the laser generating assemblies. Each laser generating assembly includes an optical resonator having a gain medium disposed between the resonator optics to guide light through the gain medium for amplification of the light by stimulated emission of light. The laser optics combine two or more input laser beams generated by the laser generating assemblies to generate a combined laser beam having a pulse energy, pulse width, or pulse repetition frequency derived from the combination of the two or more input laser beams. The laser optics also direct at least a portion of the combined laser beam as an output laser beam through an outlet of the laser module.

Description

[Background technology]

[0001] Advances in lasers and fiber optic delivery systems have facilitated the use of lasers in medical procedures. Indeed, lasers such as holmium lasers have proven useful in a variety of urological procedures, including partial or total nephrectomy, laser-assisted transurethral resections of the prostate (TURP), treatment of tumors associated with superficial bladder cancer, or fragmentation of urinary stones. Holmium laser systems for such urological procedures offer clinicians several settings, including those related to pulse energy, pulse frequency, and pulse width. However, the number of settings available for such holmium laser systems is currently limited, thereby limiting treatment options for urological procedures. What is needed is a laser module for a laser system and a method thereof that expands clinicians' options when using holmium or other lasers in medical procedures.

[0002] Disclosed herein are laser modules and methods that address the above. Summary of the Invention

[0003] Disclosed herein, in some embodiments, is a laser module including multiple independently drivable laser generating assemblies, laser optics, and a printed circuit board assembly. Each laser generating assembly of the multiple laser generating assemblies includes an optical resonator and a pump. The optical resonator includes a gain medium disposed between resonator optics configured to guide light through the gain medium for amplification of the light by stimulated emission of light. The pump is configured to deliver energy to the gain medium to excite ions, atoms, or molecules in the gain medium for stimulated emission of light. The laser optics are configured to independently combine two or more input laser beams generated by the multiple laser generating assemblies to generate an output laser beam having a pulse energy, pulse width, or pulse repetition frequency derived from the combination of the two or more input laser beams. The laser optics are also configured to direct at least a portion of the output laser beam through an outlet of the laser module. The printed circuit board assembly includes a driver configured to independently drive each laser generating assembly of the multiple laser generating assemblies with respect to at least the pulse energy, pulse width, or pulse repetition frequency of the input laser beam.

[0004] In some embodiments, the pulse repetition frequency of the pulses of the output laser beam is twice the pulse repetition frequency of any two of the two or more input laser beams.

[0005] In some embodiments, the pulses of the first input laser beam and the pulses of the second input laser beam of the two input laser beams have the same pulse repetition interval, and the pulses of the second input laser beam are delayed with respect to the pulses of the first input laser beam by half the pulse repetition interval.

[0006] In some embodiments, the pulse repetition frequency of the pulses of the output laser beam is four times the pulse repetition frequency of any of the four input laser beams of the two or more input laser beams.

[0007] In some embodiments, the pulses of the first input laser beam, the pulses of the second input laser beam, the pulses of the third input laser beam, and the pulses of the fourth input laser beam of the four input laser beams have the same pulse repetition interval. The pulses of the second input laser beam are delayed relative to the pulses of the first input laser beam by one-quarter of the pulse repetition interval. The pulses of the third input laser beam are delayed relative to the pulses of the first input laser beam by one-half the pulse repetition interval. The pulses of the fourth input laser beam are delayed relative to the pulses of the first input laser beam by three-quarters of the pulse repetition interval.

[0008] In some embodiments, a pulse of the output laser beam is a set of pulses of two or more input laser beams. In some embodiments, pulses of a first input laser beam and pulses of a second input laser beam of the two or more input laser beams have the same pulse repetition interval, and the pulses of the second input laser beam are delayed relative to the pulses of the first input laser beam by at least the pulse width of the pulses of the first input laser beam plus no more than the pulse width of the pulses of the first input laser beam.

[0009] In some embodiments, the pulse energy of the pulses of the output laser beam is about twice the pulse energy of either of two of the two or more input laser beams for half of the pulses of the output laser beam.

[0010] In some embodiments, the pulses of a first one of the two input laser beams have a pulse repetition interval that is half the pulse repetition interval of the pulses of a second one of the two input laser beams, and every other pulse of the first input laser beam coincides in time with one of the pulses of the second input laser beam.

[0011] In some embodiments, each input laser beam of the two or more input laser beams has approximately the same pulse energy and approximately the same pulse width. In some embodiments, the output laser beam is a continuous wave of pulses of two of the two or more input laser beams.

[0012] In some embodiments, pulses of a first input laser beam and pulses of a second input laser beam of two input laser beams have the same pulse width and the same pulse repetition interval, and the pulses of the second input laser beam are delayed relative to the pulses of the first input laser beam by the pulse widths of the first and second input laser beams.

[0013] In some embodiments, pulses of a first input laser beam and pulses of a second input laser beam of the two input laser beams have different pulse widths and the same pulse repetition interval, and the pulses of the second input laser beam are delayed relative to the pulses of the first input laser beam by the pulse width of the first input laser beam.

[0014] In some embodiments, the pulse width of the first input laser beam is half the pulse width of the second input laser beam. In some embodiments, the pulse energy of the output laser beams is modulated, with the first input laser beam or the second input laser beam having a greater pulse energy than the second input laser beam or the first input laser beam, respectively.

[0015] In some embodiments, the output laser beam is a continuous wave for the first input laser beam and a pulsed wave for the second input laser beam, and the peak power of the output laser beam is modulated according to the pulse repetition interval of the second input laser beam.

[0016] Also disclosed herein is a method for a laser module for a medical system. In some embodiments, the method includes an input laser driving step, an input laser combining step, and an output laser guiding step. The input laser driving step includes independently driving each laser generating assembly of the plurality of laser generating assemblies using a driver of the printed circuit board assembly in terms of at least the pulse energy, pulse width, or pulse repetition frequency of its input laser beam. The input laser driving step includes an energy pumping step. The energy pumping step includes pumping energy into a gain medium to excite ions, atoms, or molecules of the gain medium for light amplification by stimulated emission of light. The input laser combining step includes independently combining, using laser optics, two or more input laser beams generated by the plurality of laser generating assemblies to generate an output laser beam having a pulse energy, pulse width, or pulse repetition frequency resulting from the combination of the two or more input laser beams. The output laser guiding step includes guiding at least a portion of the output laser beam through an outlet of the laser module.

[0017] In some embodiments, the pulse repetition frequency of the output laser beam is twice the pulse repetition frequency of any of two of the two or more input laser beams after combining the two input laser beams with the laser optics in the input laser combining step, and the pulses of each of the two input laser beams have the same pulse repetition interval.

[0018] In some embodiments, the input laser driving step includes delaying pulses of a second input laser beam of the two input laser beams relative to pulses of a first input laser beam of the two input laser beams by half a pulse repetition interval shared by the two input laser beams.

[0019] In some embodiments, the pulse repetition frequency of the pulses of the output laser beam is four times the pulse repetition frequency of any of the four input laser beams of the two or more input laser beams after combining the four input laser beams with the laser optics in the input laser combining step, and the pulses of each input laser beam of the four input laser beams have the same pulse repetition interval.

[0020] In some embodiments, the driving of the input lasers includes delaying pulses of a second input laser beam of the four input laser beams relative to pulses of a first input laser beam of the four input laser beams by one-quarter of a pulse repetition interval shared by the four input laser beams, the driving of the input lasers includes delaying pulses of a third input laser beam of the four input laser beams relative to pulses of the first input laser beam by one-half of a pulse repetition interval shared by the four input laser beams, and the driving of the input lasers also includes delaying pulses of a fourth input laser beam of the four input laser beams relative to pulses of the first input laser beam by three-quarters of a pulse repetition interval shared by the four input laser beams.

[0021] In some embodiments, the pulses of the output laser beam are a set of pulses of the two or more input laser beams after the input laser combining step, wherein the pulses of each input laser beam of the two or more input laser beams have the same pulse repetition interval.

[0022] In some embodiments, the input laser driving step includes delaying a pulse of a second input laser beam of the two or more input laser beams relative to a pulse of a first input laser beam of the two or more input laser beams by at least a pulse width of the pulse of the first input laser beam plus no more than a pulse width of the pulse of the first input laser beam.

[0023] In some embodiments, the pulse energy of the pulses of the output laser beam is about twice the pulse energy of either of two of the two or more input laser beams for half of the pulses of the output laser beam after the input laser combining step.

[0024] In some embodiments, the step of driving the input laser includes pulsing a first input laser beam of the two input laser beams at a pulse repetition interval that is half the pulse repetition interval of a second input laser beam of the two input laser beams, where every other pulse of the first input laser beam coincides in time with one of the pulses of the second input laser beam.

[0025] In some embodiments, the step of driving the input laser includes generating each of the two or more input laser beams with approximately the same pulse energy and approximately the same pulse width.

[0026] In some embodiments, the step of driving the input lasers includes pulsing two of the two or more input laser beams to produce the output beam as a continuous wave.

[0027] In some embodiments, pulsing the two input laser beams includes pulsing a first input laser beam and a second input laser beam of the two input laser beams with the same pulse width and the same pulse repetition interval, but delaying the pulse of the second input laser beam relative to the pulse of the first input laser beam by the pulse width of the first and second input laser beams.

[0028] In some embodiments, pulsing the two input laser beams includes pulsing a first input laser beam and a second input laser beam of the two input laser beams with different pulse widths and the same pulse repetition interval, but delaying the pulses of the second input laser beam relative to the pulses of the first input laser beam by the pulse width of the first input laser beam.

[0029] In some embodiments, the pulse width of the first input laser beam is half the pulse width of the second input laser beam. In some embodiments, pulsing the first input laser beam and the second input laser beam includes pulsing the first input laser beam or the second input laser beam with a pulse energy greater than the second input laser beam or the first input laser beam, respectively, to generate an output laser beam having a modulated pulse energy.

[0030] In some embodiments, the input laser driving step includes generating a continuous wave of a first input laser beam of the two or more input laser beams and pulsing a second input laser beam of the two or more input laser beams to generate an output laser beam having a peak power modulated according to a pulse repetition interval of the second input laser beam.

[0031] These and other features of the concepts provided herein will become more apparent to those skilled in the art in view of the accompanying drawings and the following description, which describe in more detail certain embodiments of the concepts. [Brief explanation of the drawings]

[0032] [Figure 1] FIG. 1 illustrates a laser module according to some embodiments. [Figure 2] 1 illustrates a laser generation assembly of a laser module according to some embodiments. [Figure 3]1 illustrates another laser generating assembly of a laser module according to some embodiments. [Figure 4] 1 illustrates another laser generating assembly of a laser module according to some embodiments. [Figure 5] FIG. 1 illustrates a block diagram of the electronics of a laser module according to some embodiments. [Figure 6] 1A-1C provide a profile of an output laser beam resulting from combining two input laser beams according to some embodiments. [Figure 7] FIG. 10 provides a profile of an output laser beam resulting from combining four input laser beams according to some embodiments. [Figure 8] 10A-10C provide profiles of output laser beams resulting from alternative combinations of two input laser beams according to some embodiments. [Figure 9] 10A-10C provide profiles of output laser beams resulting from alternative combinations of two input laser beams according to some embodiments. [Figure 10] 10A-10C provide profiles of output laser beams resulting from alternative combinations of two input laser beams according to some embodiments. [Figure 11] 10A-10C provide profiles of output laser beams resulting from alternative combinations of two input laser beams according to some embodiments. [Figure 12] 10A-10C provide profiles of output laser beams resulting from alternative combinations of two input laser beams according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0033] Before some specific embodiments are disclosed in more detail, it should be understood that the specific embodiments disclosed herein do not limit the scope of the concepts provided herein. It should also be understood that the specific embodiments disclosed herein can have features that can be readily separated from the specific embodiment and, optionally, combined with or substituted for features of any of the other numerous embodiments disclosed herein.

[0034] Regarding the terms used herein, it should also be understood that the terms are intended to describe certain specific embodiments and do not limit the scope of the concepts provided herein. Ordinal numbers (e.g., first, second, third, etc.) are generally used to distinguish or identify different features or steps within a group of features or steps and do not provide sequential or numerical limitations. For example, "first," "second," and "third" features or steps do not necessarily have to appear in that order, and a particular embodiment including such features or steps is not necessarily limited to three features or steps. Labels such as "left," "right," "top," "bottom," "front," "back," etc. are used for convenience and do not imply, for example, a particular fixed position, orientation, or direction. Instead, such designations are used to reflect, for example, a relative position, orientation, or direction. The singular forms "one," "one," and "said" also include plural references unless the context clearly dictates otherwise.

[0035] As used herein, pulse repetition interval (PRI) is the time interval between two adjacent pulses of a laser beam. Pulse repetition frequency (PRF) is the rate of pulses of that laser beam per unit time. Pulse repetition interval and pulse repetition frequency are inversely proportional.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. As previously mentioned, advances in lasers and fiber optic delivery systems have facilitated the use of lasers in medical procedures, such as holmium lasers in a variety of urological procedures. Several settings are available to clinicians in holmium laser systems for urological procedures, including those related to pulse energy, pulse frequency, and pulse width. However, the number of settings available in such holmium laser systems is currently limited, thereby limiting treatment options for urological procedures. What is needed is a laser module and method for a laser system that expands clinicians' options when using holmium or other lasers in medical procedures.

[0037] Disclosed herein are laser modules and methods that address the above. Laser Module FIG. 1 illustrates a laser module 100 according to some embodiments.

[0038] As shown, laser module 100 includes multiple independently actuable laser generation assemblies 102a, 102b, ..., 102n, collectively referred to herein as laser generation assemblies 102, laser optics 104, and a printed circuit board assembly (PCBA) 106. Laser module 100 may further include a photodetector, such as a photodiode 108, or a photodetector array, such as a photodiode array, with laser optics 104 configured therefor.

[0039] 2-4 show multiple laser generating assemblies 102 of a laser module 100 according to some embodiments. Each laser generating assembly 102a, 102b, ..., 102n of the plurality of laser generating assemblies 102 includes an optical resonator 110 (e.g., optical resonator 110a, optical resonator 110b, ..., optical resonator 110n) paired with a pump 112 (e.g., pump 112a, pump 112b, ..., pump 112n).

[0040] The optical cavity 110 includes a gain medium 114 disposed between resonator optics configured to guide light through the gain medium 114 for amplification of the light by stimulated emission of photons γ. The gain medium 114 can include crystals including rare earth metal ion doped yttrium aluminum garnet (YAG) crystals such as holmium-doped YAG (Ho:YAG), neodymium-doped YAG (Nd:YAG), ytterbium-doped YAG (Yb:YAG), or erbium-doped YAG (Er:YAG), ceramics including rare earth metal ion doped YAG ceramics such as neodymium-doped YAG, glasses including rare earth metal ion doped phosphate or silicate glasses, semiconductors such as gallium arsenide, indium gallium arsenide, or gallium nitride, liquid solutions including one or more laser-active organic molecules such as dyes, or gases including one or more laser-active atoms or molecules such as carbon dioxide.

[0041] The resonator optics can include any number or type of optical elements, including laser mirrors, Faraday isolators, or the like, necessary to realize a linear or ring resonator for the optical resonator 110. The laser mirrors can include dielectric mirrors, dichroic mirrors, or the like, configured as highly reflective or partially transmissive flat or curved mirrors as necessary for the linear or ring resonator. For example, the optical resonator 110 of FIG. 2 is a side-pumped linear resonator including a highly reflective flat mirror 116 and a partially transmissive output coupler 118. In another example, the optical resonator 110 of FIG. 3 is a side-pumped linear resonator including a highly reflective flat mirror 116, a highly reflective curved mirror 120, and a partially transmissive output coupler 118. In another example, the optical resonator 110 of FIG. 4 is a ring resonator including a Faraday isolator 122 that transmits light in a first direction but blocks light in an opposite second direction, two highly reflective flat mirrors 116, and two partially transmissive curved mirrors 124. Each of the two partially transmitting curved mirrors 124 can be configured to transmit a different wavelength of light therethrough. In fact, one of the two partially transmitting curved mirrors 124 can function as an output coupler.

[0042] The pump 112 is configured to deliver energy E into the gain medium 114 to excite ions, atoms, or molecules in the gain medium 114 for stimulated emission of photons γ. The pump 112 may be configured to optically or electrically pump the gain medium 114 from the side and end of the gain medium 114, as in Figures 2 and 3, respectively. If the gain medium 114 is, for example, a crystal, ceramic, or glass, the pump 112 may be a laser diode or a discharge lamp. In another embodiment, if the gain medium 114 is a semiconductor, the pump 112 may be an electrical pump.

[0043] The laser optics 104 is configured to independently combine two or more input laser beams (e.g., laser beam a, laser beam b, ..., laser beam n in FIG. 1 ) generated by the multiple laser generating assemblies 102 to generate a combined laser beam having a pulse energy, pulse repetition frequency, or pulse width resulting from the combination of the two or more input laser beams. For example, the laser optics 104 may include a collimating lens 126 (e.g., collimating lens 126 a, collimating lens 126 b, ..., collimating lens 126 n) and a prism 128 (e.g., prism 128 a, prism 128 b, ..., prism 128 n) for each laser generating assembly 102 a, 102 b, ..., 102 n of the multiple laser generating assemblies 102 to combine the two or more input laser beams to generate the combined laser beam. The laser optics 104 is also configured to direct a portion, up to the entirety, of the combined laser beam as an output laser beam through an outlet of the laser module 100. It should be understood that the output laser beam referred to herein is the combined laser beam, even though any portion may be directed to a photodetector such as photodiode 108 .

[0044] If a photodiode 108 is present, the laser optics 104 may further include a beam splitter 130 or the like configured to direct a portion of the combined laser beam as a reflected laser beam to the photodiode 108. If a photodiode array is present, the laser optics 104 may further include multiple beam splitters or the like configured to direct a portion of each input laser beam as a reflected input laser beam to the photodiode array.

[0045] FIG. 5 shows a block diagram of the laser module electronics according to some embodiments. The PCBA 106 includes a driver 132 configured to independently drive each laser generating assembly 102a, 102b, ..., 102n of the multiple laser generating assemblies 102 with respect to at least the pulse energy, pulse repetition frequency, or pulse width of its input laser beam. To achieve such driving, the driver 132 provides appropriate drive currents to each laser generating assembly 102a, 102b, ..., 102n or its pump 112 according to an optical power manager 134 configured to control the power or pulse power and a pulsed wave manager 136 configured to control both the pulse width and pulse repetition frequency. For example, because pulse energy is the product of the pulse power over a period of one pulse, the optical power manager 134 and the pulsed wave manager 136 are both configured to control pulse energy. Additionally, the driver 132 can be configured to independently drive each laser generating assembly 102a, 102b, ..., 102n of the multiple laser generating assemblies 102 with respect to continuous wave operation of its input laser beam. To achieve such driving, the driver 132 can provide appropriate drive currents to each laser generating assembly 102a, 102b, ..., 102n or its pump 112 according to a continuous wave manager 138 configured to drive continuous wave operation.

[0046] The PCBA 106 also includes a microcontroller 140 and a power manager 142 coupled to a power supply 143. The microcontroller 140 includes one or more central processing units (CPUs), program memory having executable instructions, and at least a small amount of random access memory (RAM) configured to control the laser module 100. The power manager 142 is configured to manage the power distribution and consumption of the laser module 100, thereby maintaining a cooler operating temperature of the laser module 100.

[0047] When the photodiode 108 is present, the PCBA 106 also includes a photocurrent monitor 144 configured to monitor the instantaneous photocurrent generated by the photodiode 108 in accordance with the reflected laser beam, the instantaneous photocurrent being proportional to the reflected laser beam, which in turn is proportional to an output laser beam, such as from the beam splitter 130. Comparison of the instantaneous photocurrent of the reflected laser beam to an expected photocurrent of the reflected laser beam by the photocurrent comparison logic of the microcontroller 140 enables the drivers 132 to cooperatively and independently adjust the drive of any one or more laser generating assemblies 102. For example, if the output laser beam is expected to have a profile such as that provided in FIG. 6, but comparison of the instantaneous photocurrent of the reflected laser beam to the expected photocurrent of the reflected laser beam indicates that the delayed pulse corresponding to that of input laser b has reduced pulse energy, the drivers 132 are configured to cooperatively adjust the drive of laser generating assembly 102 b.

[0048] If a photodiode array is present, PCBA 106 also includes a photocurrent monitor 144, configured to monitor the parallel instantaneous photocurrent generated by the photodiode array in accordance with the reflected input laser beam. Comparison of the instantaneous photocurrent of the reflected laser beam with the expected photocurrent of the reflected input laser beam by the photocurrent comparison logic of microcontroller 140 enables drivers 132 to cooperatively and independently adjust the drive of any one or more laser generating assemblies of multiple laser generating assemblies 102. For example, if a reflected input laser beam (e.g., a reflected portion of input laser b) is expected to contribute to an output laser beam profile such as that provided in FIG. 6 as corresponding to that forming the output laser beam, but comparison of the instantaneous photocurrent of the reflected input laser beam with the expected photocurrent of the reflected input laser beam indicates that the pulses have reduced pulse energy, drivers 132 are configured to cooperatively and independently adjust the drive of the laser generating assemblies therefor.

[0049] Output laser beam profile As previously described, the laser optics 104 is configured to independently combine two or more input laser beams (e.g., laser beam a, laser beam b, ..., laser beam n in FIG. 1 ) generated by the multiple laser generation assemblies 102 to generate a combined laser beam having a pulse energy, pulse repetition frequency, or pulse width resulting from the combination of the two or more input laser beams. Figures 6-12 provide various profiles of output laser beams resulting from the combination of the two or more input laser beams, each of which provides additional options for achieving medical treatments using the output laser beam.

[0050] FIG. 6 provides a profile of an output laser beam resulting from combining two input laser beams (eg, input laser a and input laser b) of two or more input laser beams according to some embodiments.

[0051] As shown, the pulse repetition frequency of the pulses of the output laser beam is twice the pulse repetition frequency of either of the two input laser beams combined to form the output laser beam. In fact, the pulses of the first input laser beam (e.g., input laser a) and the pulses of the second input laser beam (e.g., input laser b) of the two input laser beams have the same pulse repetition interval, but to double the pulse repetition frequency of the output laser beam, the pulses of the second input laser beam are delayed relative to the pulses of the first input laser beam by half the pulse repetition interval of the output laser beam. With respect to the pulses of the first input laser beam in the output laser beam,

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[0054] The pulse widths PW1 and PW2 of the first and second input laser beams, respectively, are equal (e.g., 0.05 ms) in the output laser beam profile shown in Figure 6, but the pulse widths need not be equal. Additionally, the pulse powers P1 and P2 of the first and second input laser beams, respectively, are equal in the output laser beam profile shown in Figure 6, but the pulse powers need not be equal. In fact, any combination of pulse widths and pulse powers is possible.

[0055] FIG. 7 provides a profile of an output laser beam resulting from combining four input laser beams (e.g., input laser a, input laser b, input laser c, and input laser d) of two or more input laser beams according to some embodiments.

[0056] As shown, the pulse repetition frequency of the output laser beam pulses is four times the pulse repetition frequency of any of the four input laser beams combined to form the output laser beam. In fact, the pulses of the first input laser beam (e.g., input laser a), the second input laser beam (e.g., input laser b), the third input laser beam (e.g., input laser c), and the fourth input laser beam (e.g., input laser d) of the four input laser beams have the same pulse repetition interval, but to quadruple the pulse repetition frequency of the output laser beam, the pulses of the second input laser beam are delayed by one-quarter of the pulse repetition interval relative to the pulses of the first input laser beam, the pulses of the third input laser beam are delayed by half the pulse repetition interval relative to the pulses of the first input laser beam, and the pulses of the fourth input laser beam are delayed by three-quarters of the pulse repetition interval of the output laser beam relative to the pulses of the first input laser beam. With respect to the pulses of the first input laser beam in the output laser beam,

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[0061] The pulse widths PW1, PW2, PW3, and PW4 of the first, second, third, and fourth input laser beams, respectively, are equal (e.g., 0.05 ms) in the output laser beam profile illustrated in Figure 7, but the pulse widths need not be equal. Additionally, the pulse powers P1, P2, P3, and P4 of the first, second, third, and fourth input laser beams, respectively, are equal in the output laser beam profile illustrated in Figure 7, but the pulse powers need not be equal. In fact, any combination of pulse widths and pulse powers is possible.

[0062] FIG. 8 provides a profile of an output laser beam resulting from another combination of two input laser beams (eg, input laser a and input laser b) of two or more input laser beams according to some embodiments.

[0063] As shown, the pulses of the output laser beam are pairs of pulses of two input laser beams that are combined to form a pulse burst in the output laser beam. However, it should be understood that output laser beam pulses that are pairs of pulses of two input laser beams are only one example of output laser beam pulses that are sets of pulses of two or more input laser beams. In fact, the pulses of the output laser beam could instead be triplets of pulses of three input laser beams that are combined to form the output laser beam, quadruplets of pulses of four input laser beams that are combined to form the output laser beam, etc. For pulses of an output laser beam, which are pairs of pulses of the two input laser beams, pulses of a first input laser beam (e.g., input laser a) and pulses of a second input laser beam (e.g., input laser b) of the two input laser beams have the same pulse repetition interval, but the pulses of the second input laser beam are delayed relative to the pulses of the first input laser beam by at least the pulse width of the pulses of the first input laser beam plus no more than the pulse width of the pulses of the first input laser beam to form pulse bursts in the output laser beam. Notably, delaying the pulses of the second input laser beam relative to the pulses of the first input laser beam by at least the pulse width of the pulses of the first input laser beam plus no more than a small fraction of the pulse width of the pulses of the first input laser beam results in tighter coupling of the pulses of the first and second input laser beams. For pulses of the first input laser beam in the output laser beam,

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[0066] The pulse widths PW1 and PW2 of the first input laser beam and the second input laser beam, respectively, are equal (e.g., 0.05 ms) in the profile of the output laser beam illustrated in FIG. 8, but the pulse widths do not have to be equal. In addition, the pulse powers P1 and P2 of the first input laser beam and the second input laser beam, respectively, are equal in the profile of the output laser beam illustrated in FIG. 8, but the pulse powers do not have to be equal. In fact, any combination of pulse width and pulse power is possible.

[0067] FIG. 9 provides a profile of an output laser beam obtained from another combination of two of more than two input laser beams (e.g., input laser a and input laser b) according to some embodiments.

[0068] As shown, the pulse energy of the pulses of the output laser beam is approximately twice the pulse energy of either of the two input laser beams combined to form the output laser beam for half of the pulses of the output laser beam. To form such a modulated output laser beam (e.g., a power-modulated output laser), the pulses of a first of the two input laser beams (e.g., input laser a) have a pulse repetition interval that is half the pulse repetition interval of the pulses of a second of the two input laser beams (e.g., input laser b), and the delay is a multiple of the pulse repetition interval, so that every other pulse of the first input laser beam coincides in time with one of the pulses of the second input laser beam, optionally after a delay of the pulses of either the first or second input laser beam. For the pulses of the first input laser beam in the output laser beam:

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[0072] The pulse widths PW1 and PW2 of the first and second input laser beams, respectively, are equal (e.g., 0.05 ms) in the output laser beam profile illustrated in FIG. 9, although the pulse widths need not be equal. Additionally, the pulse powers P1 and P2 of the first and second input laser beams, respectively, are equal in the output laser beam profile illustrated in FIG. 9, although the pulse powers need not be equal. In fact, any combination of pulse widths and pulse powers is possible. Additionally, any number of two or more input laser beams can be combined to form the output laser beam.

[0073] FIG. 10 provides a profile of an output laser beam resulting from another combination of two input laser beams (eg, input laser a and input laser b) of two or more input laser beams according to some embodiments.

[0074] As shown, the output laser beam is an unmodulated continuous wave of pulses of two input laser beams combined to form the output laser beam. In fact, the pulses of a first input laser beam (e.g., input laser a) and a second input laser beam (e.g., input laser b) of the two input laser beams have the same pulse energy, pulse width, and pulse repetition interval, but the pulses of the second input laser beam are delayed relative to the pulses of the first input laser beam by the pulse widths of the first and second input laser beams to form the unmodulated continuous wave output laser beam. With respect to the pulses of the first input laser beam in the output laser beam:

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[0077] The pulse widths PW1 and PW2 of the first and second input laser beams, respectively, are equal (e.g., 0.225 ms) in the output laser beam profile illustrated in Figure 10, although the pulse widths need not be equal. Additionally, the pulse powers P1 and P2 of the first and second input laser beams, respectively, are equal in the output laser beam profile illustrated in Figure 10, although the pulse powers need not be equal. Indeed, as described below, Figure 11 provides a modulated continuous wave output laser beam formed from two input laser beams having pulses of different pulse powers and pulse widths.

[0078] FIG. 11 provides a profile of an output laser beam resulting from another combination of two input laser beams (eg, input laser a and input laser b) of two or more input laser beams according to some embodiments.

[0079] As shown, the output laser beam is a modulated continuous wave (e.g., power modulated continuous wave) of pulses of two input laser beams combined to form the output laser beam. In fact, the pulses of a first input laser beam (e.g., input laser a) and a second input laser beam (e.g., input laser b) of the two input laser beams have different pulse energies, different pulse widths, and the same pulse repetition interval, but the pulses of the second input laser beam are delayed relative to the pulses of the first input laser beam by the pulse width of the first input laser beam, which is half the pulse width of the second input laser beam, to form the modulated continuous wave of the output laser beam. In addition, the pulses of the first input laser beam have twice the pulse energy of the pulses of the second input laser beam. With respect to the pulses of the first input laser beam in the output laser beam,

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[0081]

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[0082] 10, the pulse width PW1 of the first input laser beam is half the pulse width of the second input laser beam, although the pulse width can be half the pulse width of the first input laser beam in some other relationship, such as the same as or opposite to the pulse width PW2 of the second input laser beam. Additionally, in the output laser beam profile shown in FIG. 10, the pulse power P1 of the first input laser beam is twice the pulse power of the second input laser beam, although the pulse power can be twice the pulse power of the first input laser beam in some other relationship, such as opposite to the pulse power P2 of the second input laser beam.

[0083] FIG. 12 provides a profile of an output laser beam resulting from another combination of two input laser beams (eg, input laser a and input laser b) of two or more input laser beams according to some embodiments.

[0084] As shown, the output laser beam is a modulated continuous wave (e.g., power modulated continuous wave) of two input laser beams combined to form the output laser beam. In effect, to form the modulated continuous wave output laser beam, the continuous wave of a first input laser beam (e.g., input laser a) of the two input laser beams is combined with pulses of a second input laser beam (e.g., input laser b) of the two input laser beams. The pulses of the second input laser beam have a pulse repetition frequency that modulates the pulse energy in the output laser beam. For the pulses of the second input laser beam in the output laser beam:

[0085]

number

[0086] The power P1 of the first input laser beam is half the pulse power P2 of the second input laser beam, but the power P1 and the pulse power P2 can have some other relationship. In fact, any combination of pulse widths and pulse powers is possible.

[0087] method Methods of the laser module 100 include methods of using the laser module 100 in a medical system. For example, a method of using the laser module includes the steps of driving an input laser, coupling an input laser, and guiding an output laser.

[0088] The input laser driving step includes using the driver 132 of the PCBA 106 to independently drive each laser generating assembly 102a, 102b, ..., 102n of the plurality of laser generating assemblies 102 in terms of at least the pulse energy, pulse repetition frequency, or pulse width of its input laser beam.

[0089] The input laser driving step includes an energy pumping step, which involves pumping energy into the gain medium 114 with a pump 112 to excite ions, atoms, or molecules in the gain medium 114 for light amplification by stimulated emission of light.

[0090] The input laser combining step involves using laser optics 104 to independently combine two or more input laser beams generated by the multiple laser generation assemblies 102 to generate an output laser beam having a pulse energy, pulse repetition frequency, or pulse width resulting from the combination of the two or more input laser beams.

[0091] The output laser directing step includes directing at least a portion of the output laser beam through an outlet of the laser module 100 . Additional details of each of the input laser driving and input laser combining steps are described below with respect to Figures 6-12, which provide various profiles of the output laser beam resulting from combining two or more input laser beams.

[0092] Again, FIG. 6 provides a profile of an output laser beam resulting from combining two input laser beams (e.g., laser beam a and laser beam b) of two or more input laser beams according to some embodiments.

[0093] 6, the input laser driving step can include delaying pulses of a second one of the two input laser beams (e.g., input laser b) relative to pulses of a first one of the two input laser beams (e.g., input laser a) by half the pulse repetition interval shared by the two input laser beams. After combining the two input laser beams using laser optics 104 in the input laser combining step, the pulse repetition frequency of the pulses of the output laser beam is twice the pulse repetition frequency of either of the two input laser beams.

[0094] Again, FIG. 7 provides a profile of an output laser beam resulting from combining four input laser beams (e.g., input laser a, input laser b, input laser c, and input laser d) of two or more input laser beams according to some embodiments.

[0095] 7, the input laser driving step includes delaying pulses of a second input laser beam (e.g., input laser b) of the four input laser beams relative to pulses of a first input laser beam (e.g., input laser a) of the four input laser beams by one-quarter of the pulse repetition interval shared by the four input laser beams. The input laser driving step also includes delaying pulses of a third input laser beam (e.g., input laser c) of the four input laser beams relative to pulses of the first input laser beam by half of the pulse repetition interval shared by the four input laser beams. The input laser driving step also includes delaying pulses of a fourth input laser beam (e.g., input laser d) of the four input laser beams relative to pulses of the first input laser beam by three-quarters of the pulse repetition interval shared by the four input laser beams. After combining the four input laser beams using laser optics 104 in the input laser combining step, the pulse repetition frequency of the pulses of the output laser beam is four times the pulse repetition frequency of any of the four input laser beams.

[0096] Again, FIG. 8 provides a profile of an output laser beam resulting from another combination of two input laser beams (e.g., input laser a and input laser b) of two or more input laser beams according to some embodiments.

[0097] 8, the input laser driving step includes delaying a pulse of a second input laser beam (e.g., input laser b) of the two input laser beams relative to a pulse of a first input laser beam (e.g., input laser a) of the two input laser beams by at least a pulse width of the pulse of the first input laser beam plus no more than a pulse width of the pulse of the first input laser beam, wherein the pulses of each input laser beam of the two input laser beams have the same pulse repetition interval. After combining the two input laser beams using laser optics 104 in the input laser combining step, the pulses of the output laser beam are sets (e.g., pairs) of pulses of the two input laser beams.

[0098] Again, FIG. 9 provides a profile of an output laser beam resulting from another combination of two input laser beams (e.g., input laser a and input laser b) of two or more input laser beams according to some embodiments.

[0099] 9, the input laser driving step includes pulsing a first input laser beam (e.g., input laser a) of the two input laser beams at a pulse repetition interval that is half the pulse repetition interval of a second input laser beam (e.g., input laser b) of the two input laser beams. Optionally, the input laser driving step also includes generating each input laser beam of the two input laser beams having approximately the same pulse energy and approximately the same pulse width. Nevertheless, after the input laser combining step, every other pulse of the first input laser beam is coincident in time with one of the pulses of the second input laser beam such that the pulse energy of the pulse of the output laser beam is approximately twice the pulse energy of the two input laser beams for half of the pulse of the output laser beam.

[0100] Again, Figures 10 and 11 show that the input laser driving step provides an output laser beam profile resulting from two other combinations of two input laser beams (e.g., input laser a and input laser b) of two or more input laser beams in accordance with some embodiments.

[0101] 10 and 11, the input laser driving step pulses two input laser beams to generate the output beam as a continuous wave. Pulsing the two laser beams includes pulsing a first input laser beam (e.g., input laser a) and a second input laser beam (e.g., input laser a) of the two input laser beams with the same pulse width (see FIG. 10) or different pulse widths (see FIG. 11) and the same pulse repetition interval. Considering FIG. 10, pulsing the two input laser beams also includes delaying the pulse of the second input laser beam relative to the pulse of the first input laser beam by the pulse widths of the first and second input laser beams. However, considering FIG. 11, pulsing the two input laser beams includes delaying the pulse of the second input laser beam relative to the pulse of the first input laser beam by the pulse width of the first input laser beam, which is half the pulse width of the second input laser beam. Further considering FIG. 11, pulsing the first input laser beam and the second input laser beam also includes pulsing the first input laser beam with a pulse energy greater than the second input laser beam to generate an output laser beam having modulated pulse energy.

[0102] Again, FIG. 12 provides a profile of an output laser beam resulting from another combination of two input laser beams (e.g., input laser a and input laser b) of two or more input laser beams according to some embodiments.

[0103] Considering FIG. 12, the input laser driving step includes generating a continuous wave of a first input laser beam (e.g., input laser a) of the two input laser beams, and pulsing a second input laser beam (e.g., input laser a) of the two input laser beams to generate an output laser beam having a peak power modulated according to the pulse repetition interval of the second input laser beam.

[0104] Some specific embodiments have been disclosed herein, and while those specific embodiments have been disclosed in some detail, those specific embodiments are not intended to limit the scope of the concepts provided herein. Further adaptations and / or modifications may become apparent to those skilled in the art, and the broader aspects encompass those adaptations and / or modifications as well. Thus, departures from the specific embodiments disclosed herein may be made without departing from the scope of the concepts provided herein.

Claims

1. 1. A laser module for a medical system, comprising: a plurality of independently operable laser generating assemblies, each laser generating assembly comprising: an optical resonator including a gain medium disposed between resonator optics configured to guide light through the gain medium for amplification of the light by stimulated emission of light; a pump configured to deliver energy to the gain medium to excite ions, atoms, or molecules in the gain medium for stimulated emission; a laser generating assembly including: one or more photodiodes; laser optics configured to independently combine two or more input laser beams generated by the plurality of laser generation assemblies to generate a combined laser beam, the combined laser beam including one or more reflected laser beams and an output laser beam, the laser optics configured to direct the one or more reflected laser beams to the one or more photodiodes and direct at least a portion of the output laser beam through an outlet of the laser module, the output laser beam having a pulse energy, pulse width, or pulse repetition frequency resulting from the combination of the two or more input laser beams; 1. A printed circuit board assembly comprising: a driver configured to independently drive each laser generating assembly of the plurality of laser generating assemblies with respect to at least a pulse energy, a pulse width, or a pulse repetition frequency of the input laser beam, wherein pulses of each input laser beam are delayed relative to pulses of at least one other input laser beam; a photocurrent monitor configured to monitor a photocurrent generated by the one or more photodiodes and compare the photocurrent with an expected photocurrent corresponding to the one or more reflected laser beams, the driver adjusting the driving of each laser generating assembly of the plurality of laser generating assemblies based on the comparison; and a printed circuit board assembly including: A laser module comprising:

2. 10. The laser module of claim 1, wherein the pulse repetition frequency of the pulses of the output laser beam is twice the frequency of any two of the two or more input laser beams.

3. 3. The laser module of claim 2, wherein pulses of a first input laser beam and pulses of a second input laser beam of the two input laser beams have the same pulse repetition interval, and the pulses of the second input laser beam are delayed with respect to the pulses of the first input laser beam by half the pulse repetition interval of the output laser beam.

4. 10. The laser module of claim 1, wherein the pulse repetition frequency of the pulses of the output laser beam is four times the pulse repetition frequency of four of the two or more input laser beams.

5. 5. The laser module of claim 4, wherein pulses of a first input laser beam, a second input laser beam, a third input laser beam, and a fourth input laser beam have the same pulse repetition interval, the pulses of the second input laser beam are delayed relative to the pulses of the first input laser beam by one-quarter of the pulse repetition interval, the pulses of the third input laser beam are delayed relative to the pulses of the first input laser beam by one-half of the pulse repetition interval, and the pulses of the fourth input laser beam are delayed relative to the pulses of the first input laser beam by three-quarters of the pulse repetition interval.

6. 10. The laser module of claim 1, wherein the pulses of the output laser beam are sets of pulses of the two or more input laser beams.

7. 7. The laser module of claim 6, wherein pulses of a first input laser beam and pulses of a second input laser beam of the two or more input laser beams have the same pulse repetition interval, and the pulses of the second input laser beam are delayed relative to the pulses of the first input laser beam by at least a pulse width of the pulses of the first input laser beam plus less than or equal to the pulse width of the pulses of the first input laser beam.

8. 10. The laser module of claim 1, wherein a pulse energy of a pulse of the output laser beam is about twice the pulse energy of either of two of the two or more input laser beams for half of the pulses of the output laser beam.

9. 9. The laser module of claim 8, wherein pulses of a first one of the two input laser beams have a pulse repetition interval that is half that of pulses of a second one of the two input laser beams, and every other one of the pulses of the first input laser beam coincides in time with one of the pulses of the second input laser beam.

10. 10. The laser module of claim 2, wherein each of the two or more input laser beams has approximately the same pulse energy and approximately the same pulse width.

11. 10. The laser module of claim 1, wherein the output laser beam is a continuous wave of pulses of two of the two or more input laser beams.

12. 12. The laser module of claim 11, wherein pulses of a first input laser beam and pulses of a second input laser beam of the two input laser beams have the same pulse width and the same pulse repetition interval, and the pulses of the second input laser beam are delayed relative to the pulses of the first input laser beam by the pulse widths of the first and second input laser beams.

13. 12. The laser module of claim 11, wherein pulses of a first input laser beam and pulses of a second input laser beam of the two input laser beams have different pulse widths and the same pulse repetition interval, and the pulses of the second input laser beam are delayed with respect to the pulses of the first input laser beam by the pulse width of the first input laser beam.

14. 14. The laser module of claim 13, wherein the pulse width of the first input laser beam is half the pulse width of the second input laser beam.

15. 15. The laser module of claim 12, wherein the pulse energy of the output laser beam is modulated, and the first input laser beam or the second input laser beam has a greater pulse energy than the second input laser beam or the first input laser beam, respectively.

16. 10. The laser module of claim 1, wherein the output laser beam is a continuous wave of a first input laser beam and a pulse wave of a second input laser beam, and the peak power of the output laser beam is modulated according to the pulse repetition interval of the second input laser beam.

17. A method for a laser module for a medical system including one or more photodiodes, comprising: using a driver of a printed circuit board assembly to independently drive each laser generating assembly of the plurality of laser generating assemblies with respect to at least a pulse energy, a pulse width, or a pulse repetition frequency of an input laser beam of the laser generating assembly, wherein the pulses of each input laser beam are delayed relative to the pulses of at least one other input laser beam, and the driving includes pumping energy into the gain medium using a pump to excite ions, atoms, or molecules of the gain medium for light amplification by stimulated emission of light; using laser optics to independently combine two or more input laser beams generated by the plurality of laser generation assemblies to generate a combined laser beam having a pulse energy, pulse width, or pulse repetition frequency derived from the combination of the two or more input laser beams, the combined laser beam including one or more reflected laser beams and an output laser beam, and directing the one or more reflected laser beams to the one or more photodiodes; monitoring a photocurrent generated by the one or more photodiodes and comparing the photocurrent to an expected photocurrent corresponding to the one or more reflected laser beams; and adjusting activation of each laser generating assembly of the plurality of laser generating assemblies based on the comparison; directing at least a portion of the output laser beam through an outlet of the laser module; A method comprising:

18. 18. The method of claim 17, wherein after combining two of the two or more input laser beams with the laser optics, the pulse repetition frequency of the output laser beam is twice the pulse repetition frequency of either of the two input laser beams, and pulses of each input laser beam of the two or more input laser beams have the same pulse repetition frequency.

19. 20. The method of claim 18, wherein driving each laser generating assembly of the plurality of laser generating assemblies comprises delaying a pulse of a second input laser beam of the two input laser beams relative to a pulse of a first input laser beam of the two input laser beams by half the pulse repetition interval shared by the two input laser beams.

20. 18. The method of claim 17, wherein after combining four input laser beams with the laser optics, the pulse repetition frequency of pulses of the output laser beam is four times the pulse repetition frequency of any of four input laser beams of the two or more input laser beams, and wherein pulses of each input laser beam of the four input laser beams have the same pulse repetition frequency.

21. 21. The method of claim 20, wherein driving each laser generation assembly of the plurality of laser generation assemblies comprises delaying a pulse of a second input laser beam of the four input laser beams relative to a pulse of a first input laser beam of the four input laser beams by one-quarter of the pulse repetition interval shared by the four input laser beams, delaying a pulse of a third input laser beam of the four input laser beams relative to a pulse of the first input laser beam by one-half of the pulse repetition interval shared by the four input laser beams, and delaying a pulse of a fourth input laser beam of the four input laser beams relative to a pulse of the first input laser beam by three-quarters of the pulse repetition interval shared by the four input laser beams.

22. 18. The method of claim 17, wherein after the two or more input laser beams are combined with the laser optics, the pulses of the output laser beam are a set of pulses of the two or more input laser beams, and the pulses of each input laser beam of the two or more input laser beams have the same pulse repetition interval.

23. 23. The method of claim 22, wherein driving each laser generating assembly of the plurality of laser generating assemblies comprises delaying a pulse of a second input laser beam of the two or more input laser beams relative to a pulse of a first input laser beam of the two or more input laser beams by at least a pulse width of the pulse of the first input laser beam combined with less than or equal to the pulse width of the pulse of the first input laser beam.

24. 18. The method of claim 17, wherein after the two or more input laser beams are combined with the laser optics, the pulse energy of the pulses of the output laser beam is about twice the pulse energy of any two of the two or more input laser beams for half of the pulses of the output laser beam.

25. 25. The method of claim 24, wherein driving each laser generating assembly of the plurality of laser generating assemblies comprises pulsing a first input laser beam of the two input laser beams at a pulse repetition interval that is half a pulse repetition interval of a second input laser beam of the two input laser beams, every other pulse of the first input laser beam being coincident in time with one pulse of the second input laser beam.

26. 26. The method of any one of claims 18 to 25, wherein driving each laser generating assembly of the plurality of laser generating assemblies comprises generating each input laser beam of the two or more input laser beams with approximately the same pulse energy and approximately the same pulse width.

27. 18. The method of claim 17, wherein driving each laser generating assembly of the plurality of laser generating assemblies comprises pulsing two input laser beams of the two or more input laser beams to generate the output laser beam as a continuous wave.

28. 28. The method of claim 27, wherein pulsing the two input laser beams comprises pulsing a first input laser beam and a second input laser beam of the two input laser beams with the same pulse width and the same pulse repetition interval, but delaying the pulse of the second input laser beam relative to the pulse of the first input laser beam by the pulse width of the first and second input laser beams.

29. 28. The method of claim 27, wherein pulsing the two input laser beams comprises pulsing a first input laser beam and a second input laser beam of the two input laser beams with different pulse widths and different pulse repetition intervals, but delaying the pulses of the second input laser beam relative to the pulses of the first input laser beam by the pulse width of the first input laser beam.

30. 30. The method of claim 29, wherein the pulse width of the first input laser beam is half the pulse width of the second input laser beam.

31. 31. The method of any one of claims 28 to 30, wherein pulsing the first input laser beam and the second input laser beam comprises pulsing the first input laser beam or the second input laser beam with a pulse energy greater than the second input laser beam or the first input laser beam, respectively, to generate the output laser beam with modulated pulse energy.

32. 18. The method of claim 17, wherein driving each laser generating assembly of the plurality of laser generating assemblies comprises generating a continuous wave of a first input laser beam of the two or more input laser beams, and pulsing a second input laser beam of the two or more input laser beams to generate an output laser beam having a peak power modulated according to a pulse repetition interval of the second input laser beam.

Images