Clinical evidence for efficacy of pembrolizumab in MSI-H and TMB-H advanced solid tumor: results from three cancer centers in China.

BACKGROUND: Pembrolizumab has been indicated in the treatment of solid tumors with high frequency microsatellite instability (MSI-H) or high tumor mutational burden (TMB-H); however, real-world data on the effectiveness of pembrolizumab with or without chemotherapy in this molecular subset remain limited. Our retrospective study evaluated the clinical efficacy and safety of pembrolizumab in treating advanced solid tumors with either MSI-H or TMB-H. METHODS: This retrospective study analyzed data from 116 patients with MSI-H or TMB-H advanced solid cancers who received pembrolizumab with or without chemotherapy regardless of treatment setting. We analyzed objective response rate (ORR) and progression-free survival (PFS). RESULTS: The top three cancer types were colorectal (48.6% MSI-H, 6.5% TMB-H), lung (15.4% MSI-H, 84.4% TMB-H), and gastric (15.4% MSI-H, 5.1% TMB-H). The ORR with pembrolizumab was 52.6%, including complete response (CR) observed in 8.6% (n = 10) of cases and partial responses (PR) in 43.9% (n = 51). Of the 93 patients who received first-line pembrolizumab, 52 patients achieved objective response (10 CR, 42 PR), with a median PFS of 14.0 months (95% confidence intervals [CI] 6.6-21.4). Of the 23 who received subsequent-line pembrolizumab, the ORR was 39.1%, disease control rate was 91.3%, and median PFS was 5.7 months (95% CI 3.9-7.5). Treatment-related adverse events were observed in 32 patients (27.6%), with no reported treatment-related fatal adverse events. CONCLUSION: Our study provides real-world evidence on the clinical effectiveness of pembrolizumab with or without chemotherapy in the treatment of patients with MSI-H and TMB-H advanced solid cancers.

KTA-OPO for 1742 nm laser generation driven by a composite Nd:YVO4-based self-Raman laser.

In this work, a double-end diffusion bonded Nd:YVO4 self-Raman laser was designed to drive an intracavity, noncritically-phase-matched KTiOAsO4 (KTA) optical parametric oscillator (OPO). Both conversion efficiency and output power at 1.7 µm (the wavelength of the OPO signal field) were improved by effectively reducing the thermal lens effect and increasing the effective length of self-Raman medium. At an incident pump power of 15.4 W, the output power for 1742 nm output laser reached 2.16 W with a conversion efficiency of 14%, and the output having a pulse width of 10.5 ns and a pulse repetition frequency of 90 kHz. The competition between the OPO and cascaded Raman laser was observed when the incident pump power was above 12.4 W. The results highlight that in order to improve output power at 1742 nm, it is critical that both the cascaded, second-Stokes field at 1313 nm and the signal field generated at 1534 nm from the 1064 nm field driving the KTA-OPO be minimized, if not completely suppressed. This laser system combining the processes of stimulated Raman scattering and optical parametric oscillation for the generation of laser emission at 1742 nm may find significant application across a broad range of fields including biological engineering, laser therapy, optical coherence tomography and for the generation of mid-infrared laser wavelengths.

Raman laser induced self-organization with topology in a dipolar condensate.

We investigate the ground states of a dipolar Bose-Einstein condensate (BEC) subject to Raman laser induced spin-orbit coupling with mean-field theory. Owing to the interplay between spin-orbit coupling and atom-atom interactions, the BEC presents remarkable self-organization behavior and thus hosts various exotic phases including vortex with discrete rotational symmetry, stripe with spin helix, and chiral lattices with C4 symmetry. The peculiar chiral self-organized array of square lattice, which spontaneously breaks both U(1) and rotational symmetries, is observed when the contact interaction is considerable in comparison with the spin-orbit coupling. Moreover, we show that the Raman-induced spin-orbit coupling plays a crucial role in forming rich topological spin textures of the chiral self-organized phases by introducing a channel for atoms to turn on spin flipping between two components. The self-organization phenomena predicted here feature topology owing to spin-orbit coupling. In addition, we find long-lived metastable self-organized arrays with C6 symmetry in the case of strong spin-orbit coupling. We also present a proposal to observe these predicted phases in ultracold atomic dipolar gases with laser-induced spin-orbit coupling, which may stimulate broad theoretical as well as experimental interest.

Ultra-short pulse burst laser around 1.98†µm obtained through an all-fiber nonlinear wavelength converter and Tm-doped fiber amplifier.

We report an all-fiber ultra-short pulse burst laser operating at around 1.98 µm that is obtained through a nonlinear wavelength converter and Tm-doped fiber amplifier. A mode-locked Er-doped fiber laser was first built and then amplified in subsequent amplifiers to an average power of 1.3 W. Ultra-short pulse burst output was achieved through a pulse multiplier and a fiber-pigtailed acousto-optic modulator. It was then injected into an all-fiber nonlinear wavelength converter constructed from P-doped fiber and Tm-doped fiber, obtaining an ultra-short pulse burst laser of 540 mW around 1.98 µm. Its average output power was then amplified to 4.33 W in a Tm-doped fiber amplifier with an intra-burst pulse repetition frequency of 0.9 GHz, a burst repetition frequency of 200 kHz, and a duty cycle of 2%, corresponding to about 200 pulses within each burst. This 1.98 µm pulse burst laser has enormous potential to be applied in bio-medical areas.

Clinical activity of pembrolizumab with or without chemotherapy in advanced pulmonary large-cell and large-cell neuroendocrine carcinomas: a multicenter retrospective cohort study.

BACKGROUND: Immune checkpoint inhibitors (ICI)-based combination strategies have improved the survival outcomes in advanced non-small cell lung cancers; however, data regarding their efficacy remains limited for uncommon histological types, including large-cell carcinoma (LCC) and large-cell neuroendocrine carcinoma (LCNEC). METHODS: We retrospectively analyzed a total of 60 patients with advanced LCC and LCNEC - 37 treatment-naïve and 23 pre-treated - who received pembrolizumab with or without chemotherapy. Treatment and survival outcomes were analyzed. RESULTS: Of the 37 treatment-naïve patients who received first-line pembrolizumab combined with chemotherapy, the 27 patients with LCC had an overall response rate (ORR) of 44.4% (12/27) and a disease control rate (DCR) of 88.9% (24/27); whereas 10 patients with LCNEC had an ORR of 70% (7/10) and DCR of 90% (9/10). The median progression-free survival (mPFS) was 7.0 months (95% confidence intervals [CI]: 2.2-11.8) and median overall survival (mOS) was 24.0 months (95%CI: 0.0-50.1) for first-line pembrolizumab plus chemotherapy of LCC (n = 27), whereas mPFS was 5.5 months (95%CI: 2.3-8.7) and mOS was 13.0 months (95%CI: 11.0-15.0) for first-line pembrolizumab plus chemotherapy of LCNEC (n = 10). Of the 23 pre-treated patients who received subsequent-line pembrolizumab with or without chemotherapy, mPFS was 2.0 months (95% CI: 0.6-3.4) and mOS was 4.5 months (95% CI: 0.0-9.0) for LCC and mPFS was 3.8 months (95% CI: 0.0-7.6) and mOS was not reached for LCNEC. CONCLUSION: Our study provides real-world clinical evidence of the anti-tumor activity of pembrolizumab plus chemotherapy in advanced LCC and LCNEC, indicating that this regimen could serve as a treatment option, particularly as first-line therapy, for improving the survival outcomes of patients with these rare histological subtypes of lung cancer. TRIAL REGISTRATION: NCT05023837(ESPORTA, 27/08/2021).

Sintilimab plus docetaxel as second-line therapy of advanced non-small cell lung cancer without targetable mutations: a phase II efficacy and biomarker study.

BACKGROUND: Single-agent immunotherapy is currently the recommended second-line therapy for patients with advanced non-small cell lung cancer (NSCLC) without targetable mutations; however, the objective response rate (ORR) remains low. This phase II study evaluated the efficacy of the combination therapy of sintilimab plus docetaxel and explored potential biomarkers for efficacy prediction. METHODS: Thirty patients with NSCLC without targetable mutations whose disease progressed from first-line platinum-based chemotherapy from October 2019 to December 2020 were enrolled in this single-arm, single-center, phase II trial. Sintilimab (200 mg) and docetaxel (75 mg/m2) were administered every 3 weeks until progression. The primary endpoint was ORR. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety. Biomarker analyses of blood and tissue samples were also performed. RESULTS: Among 30 patients, 11 patients had partial response, resulting in an ORR of 36.7%. The median PFS was 5.0 months (95%CI: 3.9-6.1) and OS was 13.4 months (95%CI: 5.6-21.2). The most common immune-related adverse event of any grade was hepatitis, observed in 23.3% (7/30) of patients. Treatment-emergent adverse events were manageable. Patients detected with high PD-L1 expression in circulating tumor cells (cutoff value ≥32.5% based on the median CTC-PD-L1 expression) achieved significantly higher ORR (60% versus 13.3%, p = 0.021) and significantly longer median PFS (6.0 versus 3.5 months, p = 0.011) and median OS (15.8 versus 9.0 months, p = 0.038) than those with low CTC-PD-L1 level. Patients detected with PD-L1 < 1% and CD8 ≥ 1% expression from their baseline tissue samples had significantly higher ORR (83.3% versus 12.5%, p = 0.026) but similar PFS (p = 0.62) and OS (p = 0.15). CONCLUSION: This study demonstrated the effectiveness and safety of sintilimab plus docetaxel as a second-line treatment of NSCLC without targetable mutations after progression from first-line platinum-based chemotherapy. TRIAL REGISTRATION: This study was registered in the Clinical trials registry with ClinicalTrials.gov Identifier NCT03798743 (SUCCESS).

Exosomal miR-107 antagonizes profibrotic phenotypes of pericytes by targeting a pathway involving HIF-1α/Notch1/PDGFRß/YAP1/Twist1 axis in vitro.

Microvascular pericytes have been demonstrated as an origin for myofibroblasts that produce excessive extracellular matrix (ECM) proteins such as α-smooth muscle actin (α-SMA) and type I collagen (ColIA1) and contribute to pulmonary fibrosis (PF). However, the signaling mechanism responsible for ECM production within pericytes is poorly understood. In this study, we examined exosomal miR-107 in the fibrotic phenotypes of pericytes and the pathogenesis of PF. Using RT-qPCR, MiR-107 level was compared between clinical or bleomycin-induced PF and normal pulmonary tissues. Exosomes were isolated from cultured microvascular endothelial cells (ECs) derived from either normal or PF tissues, characterized using dynamic light scattering, transmission electron microscopy, flow cytometry, Western blot, and immunofluorescence, and then applied to pericytes. The effects of exosomes or different fibrosis-related signaling molecules were examined by Western blot, and the potential regulations between the signaling molecules were identified using bioinformatic analysis and assessed by electrophoretic mobility shift assay, chromatin immunoprecipitation, luciferase assay, and RNA binding protein immunoprecipitation. MiR-107 was downregulated in clinical or experimental PF tissues and also in exosomes from PF-derived ECs. EC-derived exosomal miR-107 essentially controlled the miR-107 level and inhibited α-SMA and ColIA1 expression in pericytes. The antifibrosis effect of miR-107 was mediated through the suppression of a pathway involving HIF-1α/Notch1/PDGFRß/YAP1/Twist1, where miR-107 directly targeted HIF-1α mRNA, whereas the latter directly activated the transcriptions of both Notch1 and PDGFRß. Functionally, targeting miR-107 promoted and targeting HIF-1α abolished the fibrotic phenotypes of pericytes. Exosomal miR-107 produced by pulmonary vascular ECs may alleviate pericyte-induced fibrosis by inhibiting a signaling pathway involving HIF-1α/Notch1/PDGFRß/YAP1/Twist1.NEW & NOTEWORTHY This work reveals a novel mechanism by which pulmonary vascular endothelial cells, via regulating the transdifferentiation of microvascular pericytes into myofibroblasts, contribute to the pathogenesis of pulmonary fibrosis. Since targeting the formation of myofibroblasts may prevent the development and benefit the treatment of pulmonary fibrosis, this study provides not only mechanistic understanding but also promising therapeutic targets for pulmonary fibrosis.

Anlotinib combined with PD-1 blockade for the treatment of lung cancer: a real-world retrospective study in China.

BACKGROUND: This study evaluated the efficacy and safety of anlotinib combined with programmed cell death protein 1 (PD-1) blockade for the treatment of small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: SCLC (n = 28) and NSCLC (n = 177) patients who received treatment at Hunan Cancer Hospital between June 1, 2019, and July 1, 2020, were retrospectively analyzed. Progression-free survival (PFS) and treatment responses were compared among patients who received combination therapy of anlotinib plus PD-1 inhibitor, or monotherapy of either chemotherapy or PD-1 inhibitor. Independent prognostic factors were identified by Cox regression analysis. RESULTS: Patients with relapsed SCLC who received anlotinib plus PD-1 inhibitor as a ≥ second-line therapy (n = 14) had a significantly longer PFS than those who received PD-1 inhibitor alone (n = 14, 5.0 vs. 3.0 months; P = 0.005). For patients with previously untreated wild-type NSCLC, the combination therapy in the first-line setting (n = 6) provided a marginally longer PFS than mono-chemotherapy (n = 6, 8.0 vs. 3.0 months; P = 0.075). For patients with relapsed NSCLC, the combination therapy in the ≥ second-line setting (n = 62) resulted in significantly higher objective response rate (19.3 vs. 5.0 vs. 2.4%; P = 0.013) and longer PFS (8.0 vs. 2.0 vs. 2.0 months; P <0.001) as compared to monotherapy of either chemotherapy (n = 41) or PD-1 inhibitor (n = 62). Anlotinib and PD-1 blockade combination therapy was an independent predictive factor of longer PFS (P <0.001). CONCLUSION: The combination of anlotinib and PD-1 inhibitor has promising efficacy and manageable toxicity as a second- or later-line treatment of relapsed NSCLC and possibly for relapsed SCLC.

Clinical and molecular factors that impact the efficacy of first-line crizotinib in ROS1-rearranged non-small-cell lung cancer: a large multicenter retrospective study.

BACKGROUND: ROS1-rearranged lung cancers benefit from first-line crizotinib therapy; however, clinical and molecular factors that could affect crizotinib efficacy in ROS1-rearranged lung cancers are not yet well-elucidated. Our retrospective study aimed to compare the efficacy of chemotherapy and crizotinib in the first-line treatment of ROS1-rearranged advanced lung cancer and evaluate various clinical and molecular factors that might impact crizotinib efficacy in real-world practice. METHODS: Treatment responses, survival outcomes, and patterns of disease progression were analyzed for 235 patients with locally advanced to advanced disease who received first-line chemotherapy (n = 67) or crizotinib (n = 168). RESULTS: The overall response rate was 85.7% (144/168) for first-line crizotinib and 41.8% (28/67) for chemotherapy. Patients treated with first-line crizotinib (n = 168) had significantly longer median progression-free survival (PFS) than chemotherapy (n = 67) (18.0 months vs. 7.0 months, p < 0.001). Patients harboring single CD74-ROS1 (n = 90) had significantly shorter median PFS with crizotinib than those harboring non-CD74 ROS1 fusions (n = 69) (17.0 months vs. 21.0 months; p = 0.008). Patients with baseline brain metastasis (n = 45) had a significantly shorter PFS on first-line crizotinib than those without brain metastasis (n = 123) (16.0 months vs. 22.0 months; p = 0.03). At progression, intracranial-only progression (n = 40), with or without baseline CNS metastasis, was associated with longer median PFS than those with extracranial-only progression (n = 64) (19.0 months vs. 13.0 months, p < 0.001). TP53 mutations were the most common concomitant mutation, detected in 13.1% (7/54) of patients with CD74-ROS1 fusions, and 18.8% (6/32) with non-CD74 ROS1 fusions. Patients with concomitant TP53 mutations (n=13) had significantly shorter PFS than those who had wild-type TP53 (n = 81) (6.5 months vs. 21.0 months; p < 0.001). PFS was significantly shorter for the patients who harbored concomitant driver mutations (n = 9) (11.0 months vs 24.0 months; p = 0.0167) or concomitant tumor suppressor genes (i.e., TP53, RB1, or PTEN) (n = 25) (9.5 months vs 24.0 months; p < 0.001) as compared to patients without concomitant mutations (n = 58). CONCLUSION: Our results demonstrate that baseline brain metastatic status and various molecular factors could contribute to distinct clinical outcomes from first-line crizotinib therapy of patients with ROS1-rearranged lung cancer. CLINICAL TRIALS REGISTRATION: CORE, NCT03646994.

Clinical and molecular feature-based nomogram model for predicting benefit from bevacizumab combined with first-generation EGFR-tyrosine kinase inhibitor (TKI) in EGFR-mutant advanced NSCLC.

BACKGROUND: The combination of bevacizumab and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) could prolong progression-free survival (PFS) in patients with EGFR-mutant advanced non-small-cell lung cancer (NSCLC). Our study investigated the clinical and molecular factors that affect the efficacy of first-generation EGFR-TKI with or without bevacizumab and identify the subset of patients who can benefit from combination therapy. METHODS: Our study included 318 patients with EGFR-mutant locally advanced/advanced NSCLC treated with either first-generation EGFR-TKI combined with bevacizumab (A+T; n = 159) or EGFR-TKI monotherapy (T; n = 159). Two nomogram models to predict PFS and overall survival (OS), respectively, were constructed using two factors that impact EGFR-TKI efficacy: metastatic site and presence of concurrent mutations. The study cohort was stratified into 2 cohorts for training (n = 176) and validation (n = 142) of the nomogram model. Using the median score from the nomogram, the patients were stratified into two groups to analyze their survival outcome. RESULTS: The A+T group had significantly longer PFS (14.0 vs. 10.5 months; p < 0.001) and OS (37.0 vs. 26.0 months; p = 0.042) than the T group. Among the patients with concurrent mutations in tumor suppressor genes, those in the A+T group had significantly longer PFS and OS than the T group (PFS 14.5 vs. 8.0 months, p < 0.001; OS 39.0 vs. 20.0 months, p = 0.003). The higher scores from the nomograms were associated with the presence of brain/liver/pleural metastasis or concomitant gene mutations, which indicated a higher likelihood of shorter PFS and OS. The validation of the nomogram revealed that patients with lower scores had significantly longer PFS for the T group than those with higher scores (15.0 vs. 9.0 months, p = 0.002), but not for the A+T group (15.9 vs. 13.9 months, p = 0.256). CONCLUSIONS: Using a nomogram, our study demonstrated that the addition of bevacizumab may enhance the therapeutic effectiveness of EGFR-TKI by overcoming the negative impact of certain clinical and molecular factors on the efficacy of EGFR-TKI.

The efficacy of music therapy to relieve pain, anxiety, and promote sleep quality, in patients with small cell lung cancer receiving platinum-based chemotherapy.

PURPOSE: Chemotherapy induces a range of physical and psychological symptoms, including pain, sleep disorders, fatigue, and anxiety. We aimed to assess the efficacy of six-step music therapy in relieving pain and anxiety and improving sleep quality in lung cancer patients receiving platinum-based chemotherapy. METHODS: Between March 2013 and October 2015, we enrolled a total of 100 patients who were diagnosed with small cell lung cancer and scheduled for platinum-based chemotherapy. Patients were randomly assigned to two groups: the music therapy group (received six-step music therapy, n=50) and the control group (not received six-step music therapy, n=50). The anxiety, pain, and sleep quality of all patients were assessed using the self-rating anxiety scale (SAS), the visual analogue scale (VAS), and the Pittsburgh Sleep Quality Index (PSQI), respectively. RESULTS: There were no significant differences in the demographic characteristics and music background between the two groups. The SAS and VAS scores in the two groups were not statistically different before chemotherapy. However, patients in the music therapy group showed significantly lower SAS and VAS scores compared with the control group at both 1 day and 5 days after chemotherapy. (SAS score at 1-day post-therapy, 49.48±2.14 vs 61.46±8.8, P=0.011; SAS score at 5-day post-therapy, 39.73±1.79 vs 62.02±8.83, P=0.005; VAS score at 1-day post-therapy, 2.14±0.78 vs 4.74±1.01, P=0.005; VAS score at 5-day post-therapy, 2.06±0.79 vs 4.74±1.08, P=0.004). In addition, the total PSQI score of patients who received music therapy was also significantly higher than that of the control group after therapy (total PSQI score at 1-day post-therapy, 8.50±1.69 vs 17.81±3.01, P=0.006; total PSQI score at 5-day post-chemotherapy, 9.84±3.02 vs 18.66±2.91, P=0.012). CONCLUSION: The music therapy was an effective approach in alleviating pain and anxiety and promoting sleep quality in lung cancer patients receiving platinum-based chemotherapy. TRIAL REGISTRATION: Chinese Clinical Trial Registry (registration number: ChiCTR-TRC-13003993).

Low let-7d exosomes from pulmonary vascular endothelial cells drive lung pericyte fibrosis through the TGFßRI/FoxM1/Smad/ß-catenin pathway.

The pathogenesis of pulmonary fibrosis (PF) was mediated by the progressive deposition of excessive extracellular matrix, but little is known about the regulatory mechanisms of fibrogenesis by lung pericytes. The mouse PF model was established by treatment with bleomycin, followed by isolation of exosomes from mouse broncho-alveolar lavage fluids by the centrifuge method. Relative mRNA/microRNA levels and protein expression were assessed by qRT-PCR and Western blotting, respectively. The binding of let-7d with gene promoter was validated by dual-luciferase reporter assay. Protein interactions were verified via GST pull-down and co-immunoprecipitation. Nuclear retention of Smad3 was analysed by extraction of cytoplasmic and nuclear fraction of pericytes followed by Western blotting. Association of FoxM1 with gene promoter was detected by EMSA and ChIP-PCR methods. FoxM1 expression is significantly elevated in human lung fibroblasts of PF patients and mouse PF model. The expression of let-7d is repressed in exosomes derived from broncho-alveolar lavage fluids of PF mice. Let-7d or FoxM1 knockdown suppressed the expression of FoxM1, Smad3, ß-catenin, Col1A and α-SMA expression in mouse lung pericytes under TGF-ß1 treatment. FoxM1 overexpression elevated above gene expression in mouse lung pericytes under TGF-ß1 treatment. Let-7d directly targets TGFßRI to regulate FoxM1 and downstream gene expression in mouse lung pericytes. FoxM1 directly interacts with Smad3 proteins to promote Smad3 nuclear retention and binds with ß-catenin promoter sequence to promote fibrogenesis. Exosomes with low let-7d from pulmonary vascular endothelial cells drive lung pericyte fibrosis through activating the TGFßRI/FoxM1/Smad/ß-catenin signalling pathway.

High energy mid-infrared laser pulse output from a BaGa4Se7 crystal-based optical parametric oscillator.

We report a high energy, narrow spectral linewidth mid-infrared laser pulse output from a Nd:Y3Al5O12 laser-pumped BaGa4Se7 (BGSe) crystal-based optical parametric oscillator (OPO). Output pulse energy of 21.5 mJ was obtained at 3816 nm, with spectral width of 12 nm and pulse width of 11.4 ns, corresponding to peak power as high as 1.89 MW. A BGSe crystal with aperture size of 10mm×10mm and length of 16 mm was applied as the nonlinear crystal in a pump fed back OPO for achieving such high pulse energy output from the simple oscillator scheme.

Supersolidity around a Critical Point in Dipolar Bose-Einstein Condensates.

We explore spatial symmetry breaking of a dipolar Bose-Einstein condensate in the thermodynamic limit and reveal a critical point in the phase diagram at which crystallization occurs via a second-order phase transition. This behavior is traced back to the significant effects of quantum fluctuations in dipolar condensates, which moreover stabilize a new supersolid phase, namely a regular honeycomb pattern with high modulational contrast and near-perfect superfluidity.

Compact passively Q-switched RbTiOPO4 cascaded Raman operation.

Compact passively Q-switched RbTiOPO4 cascaded Raman laser operation has been investigated for the first time, to our knowledge. A Nd:YAG/Cr4+:YAG composite crystal was adopted for passively Q-switched fundamental laser generation. 440 mW multi-Stokes laser output with X(ZZ)X configuration according to the Porto notations was achieved under the incident pump power of 10 W. The measured spectra contained three wavelengths of 1149, 1165, and 1185 nm based on the Raman shift of 271 and 687 cm-1. Different from actively Q-switch cascaded Raman laser with Stokes wave from low order to high order oscillating in sequence, three intensity lines were output for the whole experiment in this passively Q-switched multi-Stokes laser. The output spectra could be varied and optimized based on the output coupler coating design. Output spectra not sensitive to incident pump power for passively Q-switched cascaded Raman laser have advantages in multiwavelength laser applications.

Efficient 1.7 µm light source based on KTA-OPO derived by Nd:YVO4 self-Raman laser.

An intra-cavity optical parametric oscillator (OPO) emitting at 1.7 µm derived by Nd:YVO4 self-Raman laser is demonstrated in this Letter, with a KTiOAsO4 (KTA) crystal used as nonlinear optical crystal. A laser diode end-pumped acousto-optic Q-switched Nd:YVO4 self-Raman laser at 1176 nm was employed as the pump source. At an incident pump power of 12.1 W and a pulse repetition frequency of 60 kHz, average output power up to 1.2 W signal light at 1742 nm was obtained, with diode-to-signal conversion efficiency of 10%. The pulse width was about 11 ns and spectral line width was less than 0.5 nm for the signal light. The results show that compact intra-cavity KTA-OPO derived by Nd:YVO4 self-Raman laser is an efficient method for 1.7 µm waveband laser generation, with potential applications in biological imaging, laser therapy, special materials processing, etc.

Long-Range Interactions and Symmetry Breaking in Quantum Gases through Optical Feedback.

We consider a quasi-two-dimensional atomic Bose-Einstein condensate interacting with a near-resonant laser field that is backreflected onto the condensate by a planar mirror. We show that this single-mirror optical feedback leads to an unusual type of effective interaction between the ultracold atoms giving rise to a rich spectrum of ground states. In particular, we find that it can cause the spontaneous contraction of the quasi-two-dimensional condensate to form a self-bound one-dimensional chain of mesoscopic quantum droplets, and demonstrate that the observation of this exotic effect is within reach of current experiments.

Cavity-Assisted Single-Mode and Two-Mode Spin-Squeezed States via Phase-Locked Atom-Photon Coupling.

We propose a scheme to realize the two-axis countertwisting spin-squeezing Hamiltonian inside an optical cavity with the aid of phase-locked atom-photon coupling. By careful analysis and extensive simulation, we demonstrate that our scheme is robust against dissipation caused by cavity loss and atomic spontaneous emission, and it can achieve significantly higher squeezing than one-axis twisting. We further show how our idea can be extended to generate two-mode spin-squeezed states in two coupled cavities. Because of its easy implementation and high tunability, our scheme is experimentally realizable with current technologies.